tag:theconversation.com,2011:/au/topics/myopia-4924/articlesMyopia – The Conversation2024-01-21T13:00:13Ztag:theconversation.com,2011:article/2207532024-01-21T13:00:13Z2024-01-21T13:00:13ZUndergoing cataract surgery when it’s not necessary? Some do it to improve their eyesight, but it’s not without risk<figure><img src="https://images.theconversation.com/files/568296/original/file-20231220-21-m59siq.jpg?ixlib=rb-1.1.0&rect=2%2C0%2C989%2C666&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">For some years now, it has been possible to have surgery to replace the crystalline lens, the natural lens of the eye, with an implant.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Judy is an accomplished consultant who regularly travels for business meetings. She came to see me because she was finding her contact lenses uncomfortable and wanted to explore other options — notably surgical alternatives.</p>
<p>One option was to replace her lens with an implant. This surgery is similar to cataract surgery, but offered to patients who do not have this condition. However, it is not without risks.</p>
<p>As an optometrist with expertise in contact lenses, dry eye treatment and pre- and post-operative management of eye surgery, I had the experience required to help Judy.</p>
<h2>Dry eyes</h2>
<p>I started by doing a clinical assessment of Judy. When she came to see me, she was about to turn 53, had myopia (can’t see far), astigmatism (images stretched far and near) and presbyopia (can’t see near) caused by age.</p>
<p>She hated glasses and didn’t want to wear them in front of her customers, which is why she had undergone laser surgery to correct her myopia 15 years earlier.</p>
<p>At age 45, when presbyopia appeared, Judy had to be refitted with contact lenses. Around the time of menopause, at age 51, she developed some symptoms of dry eyes, <a href="https://pubmed.ncbi.nlm.nih.gov/28706404/">which had increased in the months before she came to see me</a>.</p>
<p>Changes in lens materials, care solutions or wearing mode (one day) had little effect. The arid environments (car interiors, airplanes, recycled office air) to which she was regularly exposed contributed to her symptoms. She also spent quite a number of hours in front of a computer screen, and as a result, blinked less frequently, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8439964/">which in turn increased her visual discomfort</a>.</p>
<p>Clinical examination showed that she did, indeed, suffer from dry eyes. She had a reduced volume of tears, <a href="https://crstoday.com/articles/2011-may/focus-on-complications-and-complexity-dry-eye-after-lasik">a side effect of her laser surgery</a>. Her cornea showed a dry, altered area, which we attributed to incomplete closure of the eyelids during sleep, no doubt induced by the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7154208/">cosmetic eyelid surgery she had had three years prior</a>. And then there were the consequences of her medication: some antidepressants have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8884704/">drying effects on the eye</a>.</p>
<h2>A step-by-step approach</h2>
<p>Judy’s vision problems were compounded by eye health issues.</p>
<p>All dry eyes have an impact on quality of vision, whatever the method of correction that’s used. So the first thing to do was to restore the balance — and treat her dry eyes.</p>
<p>Past surgery had left its mark, and there is no turning back the clock. So how to proceed in this situation?</p>
<p>As far as the eyes are concerned, the <a href="https://www.tfosdewsreport.org/public/images/TFOS_DEWS_II_Management_ther.pdf">first step</a> is to ensure intensive lubrication (full artificial tears, with no chemical preservatives). An ointment should also be applied at bedtime to protect the cornea during sleep. Topical cyclosporine should be considered because of <a href="https://pubmed.ncbi.nlm.nih.gov/33299295/">its action on tear stability</a>.</p>
<p>Furthermore, soft contact lenses can exacerbate dry eyes. Fortunately, other alternatives exist. <a href="https://sclerallens.org/for-patients-2/what-are-scleral-lenses/">Scleral lenses</a> are large rigid lenses that create a tear reservoir, which helps to <a href="https://healthcare.utah.edu/healthfeed/2022/08/scleral-contact-lenses-might-be-best-solution-youve-never-heard-of-dry-eye">reduce dry eye symptoms</a>. Despite their large diameter, these lenses are very comfortable because they rest on the white of the eye (the sclera) without touching the cornea. Visually, they can compensate for myopia, astigmatism and presbyopia.</p>
<p>I suggested these lenses to Judy. However, from her reaction I understood that she was looking for a surgical alternative instead.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/567134/original/file-20231221-16-qled5m.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="scleral lens" src="https://images.theconversation.com/files/567134/original/file-20231221-16-qled5m.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/567134/original/file-20231221-16-qled5m.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/567134/original/file-20231221-16-qled5m.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/567134/original/file-20231221-16-qled5m.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/567134/original/file-20231221-16-qled5m.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/567134/original/file-20231221-16-qled5m.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/567134/original/file-20231221-16-qled5m.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Scleral lenses are large, rigid lenses that create a reservoir of tears.</span>
<span class="attribution"><span class="source">(Langis Michaud)</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<h2>Lens exchange, with clear crystalline lenses as an option</h2>
<p>Laser enhancement is not an option <a href="https://myvision.org/lasik/how-many-times/">when the cornea becomes too thin</a>.</p>
<p>However, for some years now, it has been possible to have surgery to replace the crystalline lens, the natural lens inside of the eye, with an implant. Similar to cataract surgery, this procedure is carried out in the absence of any pathology of this type, on patients who are generally younger (aged 50-65) and healthy. And it is currently quite popular.</p>
<p>The advantage is that this implant can correct the majority of visual defects — unlike Lasik. In Judy’s case, it would be a multifocal (distance and near vision) and toric (astigmatism) lens implant.</p>
<p>Judy was immediately interested in this option. She assumed that this surgery would permanently free her from the need for contact lenses or glasses.</p>
<h2>A procedure with potential risks</h2>
<p>All surgery carries risks. In the presence of disease or pathology, the ophthalmologist’s decision to operate should, in theory, be based on a rigorous assessment of the level of risk compared to expected benefits.</p>
<p>In the case of a clear lens exchange, where no pathology is present, the question of risks versus benefits must be considered differently. We are essentially talking about non-essential, non-urgent cosmetic surgery. The risk remains, but the benefit is less obvious and more related to the patient’s personal satisfaction, which may vary a lot based on our own perspective.</p>
<p>While cataract surgery is considered to be a safe procedure, the same cannot always be said of <a href="https://www.sciencedirect.com/science/article/abs/pii/B9780323035996500638">clear lens exchange</a>. The younger the patient, the greater the risk of complications. Other factors specific to the patient <a href="https://www.aao.org/eyenet/article/refractive-lens-exchange-debate">may also weigh in the balance</a>. Before proceeding, the condition must be rigorously assessed.</p>
<p>The retina of every myopic person is <a href="https://pubmed.ncbi.nlm.nih.gov/22772022/">at risk of tearing</a>. This is a possible complication of cataract and lens surgeries <a href="https://www.reviewofophthalmology.com/article/a-review-of-refractive-lens-exchange">that should not be underestimated</a>. The high myopic retina is also stretched and <a href="https://pubmed.ncbi.nlm.nih.gov/29265742/">can deteriorate beyond the age of 60</a>, like a cinema screen that becomes cracked. Vision automatically deteriorates.</p>
<p>A multifocal implant requires a perfect retina to ensure good vision. Since Judy was highly myopic, she cannot be guaranteed perfect vision for life following clear lens exchange.</p>
<p>Not to mention that, like her mother and grandmother, she could one day develop macular degeneration. In this case, as well, the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7575463/">vision of the multifocal implant would be greatly affected</a>.</p>
<p>Multifocal implants are often associated with the perception of halos and glare, particularly in the evening. While the majority of patients tolerate these side effects after surgery, they can become very disturbing over the long term, as they <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5747227/">persist over time</a>. It may be worst in the presence of eye dryness. Moreover, the procedure is not entirely reversible — removal of the implants can have significant consequences.</p>
<p>So replacing Judy’s lens didn’t seem to be the best option, at least for the moment. In the meantime, she decided to consider scleral lenses and to optimize the treatment of her dry eyes.</p>
<p>She left satisfied, having explored her options with the person who knows her eyes best — her optometrist!</p><img src="https://counter.theconversation.com/content/220753/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Langis Michaud ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>It is possible to have surgery to replace the crystalline lens, the natural lens of the eye, with an implant — without having a cataract. But surgery has risks.Langis Michaud, Professeur Titulaire. École d'optométrie. Expertise en santé oculaire et usage des lentilles cornéennes spécialisées, Université de MontréalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1990132023-02-01T16:07:35Z2023-02-01T16:07:35ZThe true relationship between screens, books and nearsightedness<figure><img src="https://images.theconversation.com/files/507539/original/file-20230201-11-q2h3vk.jpg?ixlib=rb-1.1.0&rect=22%2C0%2C2474%2C1666&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/es/image-photo/kids-reading-book-under-blanket-elder-1071593237">Shutterstock / EvgeniiAnd</a></span></figcaption></figure><p>At one time or another we have surely heard or read that the excessive use of screens is causing an increase in cases of nearsightedness. Moreover, it is said that this relationship is direct, meaning that screens are responsible for the fact that more and more people around the world are nearsighted. Not surprisingly, there are also studies that conclude that <a href="https://www.nature.com/articles/519276a">children who spend more time in front of books or screens develop more nearsightedness than those who do not</a>.</p>
<p>And not only that. We have always assumed that nearsightedness and the use of glasses is directly related to performing tasks that require a special visual effort. Or to very studious people, or to avid life-long book readers.</p>
<p>Since we have recently replaced many of these tasks that involved reading paper with electronic screens, we have shifted the responsibility from one culprit to another.</p>
<p>However, this long-assumed direct relationship has not been scientifically proven. Although it is considered to be true because of the correlation/causation hypothesis, it is important to be careful with these parallels, since correlation does not always imply causation.</p>
<p>Tyler Vigen, a Harvard lawyer, does an excellent job of explaining this. On his website <a href="https://www.tylervigen.com/spurious-correlations">Spurious Correlations</a>, he has been carrying out a statistical experiment with arbitrary data obtained from different sources for years – data that when overlapped on graphs generates some of the most far-fetched correlations. For example, it can be deduced from the data that between 2000 and 2009 there was a correlation between the increase in per capita cheese consumption and deaths caused by becoming entangled in bedsheets. Sounds absurd, right?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/437541/original/file-20211214-13-sf4m87.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/437541/original/file-20211214-13-sf4m87.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/437541/original/file-20211214-13-sf4m87.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=237&fit=crop&dpr=1 600w, https://images.theconversation.com/files/437541/original/file-20211214-13-sf4m87.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=237&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/437541/original/file-20211214-13-sf4m87.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=237&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/437541/original/file-20211214-13-sf4m87.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=297&fit=crop&dpr=1 754w, https://images.theconversation.com/files/437541/original/file-20211214-13-sf4m87.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=297&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/437541/original/file-20211214-13-sf4m87.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=297&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Correlation between per capita cheese consumption and deaths by becoming entangled in bedsheets.</span>
<span class="attribution"><a class="source" href="https://www.tylervigen.com/spurious-correlations">Tyler Vigen / Spurious Correlations</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>What is certain is that the increase in cases of nearsightedness is real and cannot be entirely explained by genetic factors. Therefore, it is necessary to look at environmental factors.</p>
<h2>Accomplices – but not the main culprit</h2>
<p>Are screens – or rather their excessive use – the cause of nearsightedness? The latest studies suggest that they are not directly responsible.</p>
<p>Nearsightedness, which is the difficulty focusing on distant objects, occurs when the eyeball is too long relative to the focusing power of the eye’s cornea and lens. This causes light rays to be directed to a point before the retina.</p>
<p>We are also nearsighted when the cornea, the lens or both are too curved for the length of our eyeball. In some cases, <a href="https://www.mayoclinic.org/diseases-conditions/nearsightedness/symptoms-causes/syc-20375556">all of these factors occur simultaneously</a>.</p>
<p>These anomalies are corrected with lenses that transmit light information to the back of our eye.</p>
<p>The process by which an eye develops nearsightedness is not entirely known, but we do know that for our vision to develop correctly we need to promote and <a href="https://iovs.arvojournals.org/article.aspx?articleid=2772538">practice both near and distance vision</a>.</p>
<p>In this sense, it seems logical to suspect that ongoing exposure to screens from an early age at a time when the eye is still maturing may favour the development of vision of near objects, to the detriment of distance vision. However, there is not enough data to conclude that this causes nearsightedness to occur.</p>
<h2>Eye fatigue</h2>
<p>No one disputes that <a href="https://pubmed.ncbi.nlm.nih.gov/30663136/">excessive use of screens</a> causes “eye fatigue”, also known as “computer syndrome”, which causes redness, stinging and itchy eyes, dry eyes (or conversely, constant tearing), headache, etc. This occurs because when we look at a screen, we blink less (unconsciously), we stare at a specific point for a long time or from an inappropriate angle and we expose ourselves to the excessive brightness of these devices.</p>
<p>What can we do to fight it? Don’t bother <a href="https://onlinelibrary.wiley.com/doi/10.1111/opo.12738">with blue light filters</a> – which are unfairly blamed. The best recommendation to reduce the signs of eye fatigue is to blink frequently and take breaks <a href="https://www.optometrytimes.com/view/deconstructing-20-20-20-rule-digital-eye-strain">following the 20/20/20 rule</a>. In other words, every 20 minutes, take a 20-second break and look at (and try to focus on) an object 20 feet (6 metres) away.</p>
<p>If you look through a window and with light, even better. Why with light? Because it is suspected that one of the possible culprits for the development of nearsightedness is a lack of light.</p>
<h2>Lack of light</h2>
<p>Indeed, it has been proven that children who read a lot, whether on paper or on a digital screen are generally <a href="https://pubmed.ncbi.nlm.nih.gov/26497977/">less exposed to sunlight during the day</a>. And, it has recently been <a href="https://iovs.arvojournals.org/article.aspx?articleid=246623">demonstrated</a> that there is a relationship between nearsightedness and a lack of sunlight.</p>
<p>It seems that solar radiation (especially high-energy radiation, such as blue and <a href="https://pubmed.ncbi.nlm.nih.gov/28063778/">violet light</a>) would stimulate <a href="https://www.pnas.org/content/118/22/e2018840118">dopamine release by retinal amacrine cells</a> (another type of cell other than photoreceptors). This would inhibit the growth of the eye, avoiding the typical elongation that leads to nearsightedness.</p>
<p>There is also experimental evidence that shows that in different animal species, including monkeys, exposure to high-energy violet light could <a href="https://pubmed.ncbi.nlm.nih.gov/22169102/">protect against nearsightedness</a>.</p>
<p>In short, all signs point to the fact that neither books nor electronic devices are directly to blame for the increase in nearsightedness around the world. They have only become accomplices in this phenomenon by keeping children away from sunlight.</p>
<hr>
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<p class="fine-print"><em><span>Conchi Lillo no recibe salario, ni ejerce labores de consultoría, ni posee acciones, ni recibe financiación de ninguna compañía u organización que pueda obtener beneficio de este artículo, y ha declarado carecer de vínculos relevantes más allá del cargo académico citado.</span></em></p>Evidence suggests that neither books nor electronic devices are directly to blame for the increase in myopia worldwide. Rather, they enhance this phenomenon by keeping children out of the sunlight.Conchi Lillo, Profesora titular de la Facultad de Biología, investigadora de patologías visuales, Universidad de SalamancaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1931922022-10-25T20:22:51Z2022-10-25T20:22:51ZDevelopment of vision in early childhood: No screens before age two<figure><img src="https://images.theconversation.com/files/491691/original/file-20221025-22-wx4aqi.jpg?ixlib=rb-1.1.0&rect=14%2C7%2C979%2C655&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Electronic devices are not, in and of themselves, a source of visual problems. Using these devices inappropriately can interfere with the natural development of the eye, as well as reading and learning skills. </span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Things are busy on a rainy Saturday afternoon when I make a trip to the mall to finalize some back-to-school shopping. I pass by a lot of people, including several parents with young children under two years old, in strollers, and am struck by the fact that all of the children have a tablet or phone in their hands. Has technology become the ultimate tool for keeping children calm?</p>
<p>As an optometrist and eye health expert, this observation saddens me every time I see it, since I know all the harmful effects such exposure to electronic tools can have on children.</p>
<p>These effects are all the more critical during the first years of life, both on the <a href="https://pubmed.ncbi.nlm.nih.gov/34625399/">visual level</a> and on the <a href="https://pubmed.ncbi.nlm.nih.gov/36190219/">cognitive and social development of children</a>.</p>
<h2>Visual development of children</h2>
<p>The human eye develops <a href="https://www.nationwidechildrens.org/family-resources-education/health-wellness-and-safety-resources/helping-hands/infant-vision-birth-to-one-year">through stimulation</a>. The quality of the optical stimulus influences the growth of the eyeball via a complex and balanced mechanism. At birth, the eye is hyperopic, that is to say, its power is not perfectly adjusted to its size. A child sees at short distances and is barely able to distinguish a shadow when grandpa comes to the bedroom door.</p>
<p>In the first few weeks, the eye grows, the retina matures and a balance is established between the growth of the eyeball and the power of the inner lens. At six months of age, each of the toddler’s two eyes has the vision of an adult eye. From this moment on, the eyes will develop their coordination, in order to generate vision in three dimensions. It’s also starting at the age of six months that the communication between the eyes develops in the visual brain as well.</p>
<p>Billions of neurological connections will have to be made during the <a href="https://opto.umontreal.ca/clinique/pdf/EFFETS%20DES%20ECRANS%20SUR%20LE%20D%C3%89VELOPPEMENT%20VISUEL%20DES%20ENFANTS.pdf">first eight years of life</a>. This maturation time is long, but necessary, considering that <a href="https://www.sciencedirect.com/science/article/pii/S0149763413001917">more than a third of the brain’s neurons are dedicated to vision</a>.</p>
<h2>A question of distance</h2>
<p>Electronic devices are not, in themselves, a source of visual problems. Rather, the inappropriate use of these devices can interfere with the natural development of the eye, as well as reading and learning skills.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/489407/original/file-20221012-17-g43eu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two small children with glasses sitting on white chairs : a boy with a tablet computer, a girl with a cell phone" src="https://images.theconversation.com/files/489407/original/file-20221012-17-g43eu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/489407/original/file-20221012-17-g43eu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/489407/original/file-20221012-17-g43eu3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/489407/original/file-20221012-17-g43eu3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/489407/original/file-20221012-17-g43eu3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/489407/original/file-20221012-17-g43eu3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/489407/original/file-20221012-17-g43eu3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">For normal visual development, it is recommended that exposure to electronic devices be avoided between the ages of zero and two years.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>The first thing to consider is viewing distance. The eye is designed to look at a near distance that is about equal to the length of the forearm (distance from the elbow to the fingertips of the hand). That means about <a href="https://www.sciencedirect.com/science/article/pii/S0042698913000795">30 cm for a young child, and 40 cm for an adult</a>. However, tablets and phones are held on average 20-30 cm from the eye, and this distance <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/cxo.12453">becomes shorter with prolonged exposure</a>. The visual effort required to maintain a clear image at this distance is therefore doubled.</p>
<p>A distance that is too short influences the quality of the retinal image (and therefore visual development) and causes <a href="https://books.google.ca/books?hl=fr&lr=&id=jGGROHBFYt8C">excessive eye fatigue</a>. It is also important to understand that when eyes must accommodate short distances, they automatically converge towards the nose in order to focus at the normal reading distance. Too much effort spent accommodating the short distance is therefore accompanied by a greater than normal convergence. As the eye cannot maintain this prolonged effort over a long period of time, it will relax its effort and the perceived image will become blurred for a while, a sensory penalty that we want to avoid. After a period of rest, the eye will resume its effort, and this alternation between the clearness and the blur will continue as long as attention to the close image is required. So, ideally, the tablet or phone should always be kept at the distance of the forearm.</p>
<h2>Constant stimulation is not recommended</h2>
<p>The use of electronic tools, with games or videos, requires a constant attention span, without breaks. This is the second factor to consider. When a child draws in a notebook or reads a paper book, he or she will instinctively stop at some point, look elsewhere, far away, and become interested in something else around them. These pauses and breaks are beneficial <a href="https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y">for the visual system to recover from its effort</a>. Focusing on targets at a distance is also beneficial to the child’s visual development. With electronic tablets, it is not uncommon to see children doing sessions of more than two to three hours continuously, without looking up from the screen.</p>
<p>The visual apparatus of children from zero to two years old is simply not sufficiently developed and robust to undergo such stress from constant stimulation in front of the screen. In particular, the structural elements of the sclera (the deep layer of the eye), which give the eye rigidity and determine its size, develop between zero and two years of age and then stabilize. The visual stimulus at these ages can interfere and therefore <a href="https://www.researchgate.net/publication/335108098_Scleral_structure_and_biomechanics">influence the development of visual defects and pathology in later life</a>.</p>
<p>It is also important to note that the screen can emit blue light. Children’s eyes do not filter these rays like those of an adult. This means that children are exposed to more blue light, which may stimulate nearsightedness and disrupt the secretion of melatonin, <a href="https://www.myopiainstitute.com/eye-care/how-blue-light-affects-your-vision-and-overall-health/">which regulates our biological clock</a>. This can disrupt the naps necessary for children of this age, as well as sleep during the night. Sleep loss can also lead to myopia.</p>
<h2>Let’s learn about electronics</h2>
<p>For normal visual development, it is therefore recommended to <a href="https://publications.aap.org/pediatrics/article/128/5/1040/30928/Media-Use-by-Children-Younger-Than-2-Years?_ga=2.208746386.1459529850.1665228699-655911314.1665228699?autologincheck=redirected?nfToken=00000000-0000-0000-0000-000000000000">avoid all exposure to electronic devices between the ages of zero and two</a>. The exception would be occasional video conversations, under the supervision of a parent, to say hello to a grandparent who lives far away, for a few minutes.</p>
<p>From the age of two years on, an hour of exposure per day can be considered, especially to consult educational sites, always accompanied by a parent or an educator.</p>
<p>When the visual system is mature, around the age of six to eight, exposure can be increased gradually, without exceeding two to three hours per day, with 10-minute breaks every hour. Electronic device use should be avoided during meals, family activities, and at least one hour before sleep.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/489410/original/file-20221012-24-ip7l62.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Young mother holding her cute, crying baby daughter, looking at a tablet during a virtual video call business or family meeting at a distance" src="https://images.theconversation.com/files/489410/original/file-20221012-24-ip7l62.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/489410/original/file-20221012-24-ip7l62.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/489410/original/file-20221012-24-ip7l62.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/489410/original/file-20221012-24-ip7l62.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/489410/original/file-20221012-24-ip7l62.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/489410/original/file-20221012-24-ip7l62.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/489410/original/file-20221012-24-ip7l62.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rare video conversations, with parental supervision, to wave to a grandparent from a distance, for a few minutes, can be considered.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<h2>Let’s play outside!</h2>
<p>The best advice for successful visual development is to encourage exposure to outdoor light for <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6678505/#:%7E:text=Each%20additional%20hour%20of%20daily,by%2013%25%20%5B23%5D.">at least one hour per day, ideally two hours</a>. We are talking about playing, walking, and activities that are done outside. The amount of light is then much greater than indoors, which would stimulate the production of dopamine, a chemical mediator essential to regulating the growth of the eye. This is the most effective way to prevent the onset of myopia in children.</p>
<p>It is also important to make sure that a child’s visual system is normal and developing naturally. Therefore, the first examination by an optometrist should be done at six months of age (to validate that the eye has normal optics and that there are no congenital defects), and then at three years of age to evaluate eye coordination. If everything is normal, the next examination will take place at five years of age, and annually thereafter, <a href="http://nada.ca/wp-content/uploads/2018/09/BK-ChildrenAndTheirVision-2018-EN.pdf">considering that vision can change rapidly</a>.</p>
<p>In the case of an abnormality, the earlier we intervene in the process, the easier it is to restore normal oculo-visual function, either by exercise or by optical means.</p>
<p>By following these recommendations for visual hygiene, we will protect children’s visual system and ensure their normal development.</p>
<p>And let’s not forget that the most beautiful screen in the world is nature! We should offer it to our children more often.</p><img src="https://counter.theconversation.com/content/193192/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Langis Michaud ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>The impact of using electronic devices is critical during the first years of life, both visually and on the cognitive and social development of the child.Langis Michaud, Professeur Titulaire. École d'optométrie. Expertise en santé oculaire et usage des lentilles cornéennes spécialisées, Université de MontréalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1904512022-09-13T08:48:27Z2022-09-13T08:48:27ZUK-Africa ties: future looks gloomy under Liz Truss as political myopia reigns<figure><img src="https://images.theconversation.com/files/484268/original/file-20220913-12-o2cvok.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Britain's new prime minister, Liz Truss.
</span> <span class="attribution"><span class="source">EFE-EPA/Stuart Brock</span></span></figcaption></figure><iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/uk-africa-ties-future-looks-gloomy-under-liz-truss-as-political-myopia-reigns-190451&bgColor=F5F5F5&color=D8352A&playColor=D8352A" width="100%" height="110px"></iframe>
<p>Britain has a new prime minister in <a href="https://theconversation.com/liz-truss-who-is-the-uks-new-prime-minister-and-why-has-she-replaced-boris-johnson-189713">Liz Truss</a>. For African leaders wondering what the new administration might mean for UK-Africa relationships, the view must be pretty gloomy. </p>
<p>British politics has been solidly inward-looking for the past two (post-Brexit Conservative) prime ministers – <a href="https://www.gov.uk/government/people/theresa-may">Theresa May</a> and <a href="https://www.britannica.com/biography/Boris-Johnson">Boris Johnson</a>. It shows few signs of changing. Looking at the UK’s shifts in relationship with African countries over the past three decades, I see little prospect of African issues rising up the political agenda. And little chance of an active Africa policy, whether at a continental or regional level, before the next general election.</p>
<p>The election must be held <a href="https://metro.co.uk/2022/06/07/when-is-the-next-uk-general-election-and-could-it-be-brought-forward-16782836/">by January 2025</a>, but is likely to be sooner. </p>
<p>Aid levels are unlikely to be restored. Nor is UK aid likely to be placed back in an independent government department. In addition, British politicians are unlikely to look beyond domestic and European crises. The result is that Africa is likely to feature in British high-level politics only when it is in the government’s narrow self-interest. </p>
<p>Nevertheless, UK policy will still have impact on the continent. A retreat from climate-emergency pledges, and continuing cuts in aid, will create real harm in many vulnerable African states. Sadly, there will be little scope for their voices to be heard in response.</p>
<h2>Shifting priorities</h2>
<p>Africa and the UK lack the close (some would argue too close) formal political, economic and military linkages of Franco-African relationships. Still, Africa has in the past been a much bigger part of the UK’s political conversation. </p>
<p>The creation of an independent aid ministry – the <a href="https://www.gov.uk/government/organisations/department-for-international-development">Department for International Development</a> – by the Labour government <a href="https://www.jstor.org/stable/3993255">in 1997</a> was a key platform for building relationships.</p>
<p>It was also key to raising African politics and issues within the UK government. With both prime minister <a href="https://www.britannica.com/biography/Tony-Blair">Tony Blair</a> (1997-2007) and finance minister <a href="https://www.gov.uk/government/history/past-prime-ministers/gordon-brown">Gordon Brown</a> (2007-2010) interested in African prospects and development, close ties were forged. Through the Department for International Development, links with civil society voices were also stronger.</p>
<p>The transition to a Conservative government <a href="https://www.researchgate.net/publication/228198676_The_British_General_Election_of_2010_The_Results_Analysed">in 2010</a> (initially as part of a coalition) saw little change. Indeed, the raising of aid spending to <a href="https://www.ft.com/content/d217e3e4-7bc8-11e4-b6ab-00144feabdc0">0.7% of gross national income</a> – an increase of £1 billion – expanded the Department for International Development. At the time, other domestic-focused departments faced <a href="https://www.theguardian.com/society/2020/mar/03/lost-decade-hidden-story-how-austerity-broke-britain">severe cuts to their budgets</a>. </p>
<p>The first conservative minister of international development, <a href="https://www.gov.uk/government/people/andrew-mitchell">Andrew Mitchell</a> (2010-2012), had long-standing interests in the continent. He developed close relationships with key leaders, including Rwanda’s Paul Kagame. He also maintained close ties with the Ethiopian government, among others. Prime minister <a href="https://www.gov.uk/government/news/david-cameron-a-new-future-for-africa">David Cameron</a> (2010-2016) was also interested in Africa, as a visible indication of his ambitions for a strong UK global role.</p>
<p>Since the Brexit referendum <a href="https://theconversation.com/brexit-five-years-after-the-referendum-here-are-five-things-weve-learned-162974">in 2016</a>, however, Africa has slipped from its precarious but tangible place in UK political discourse. The dismantling of the Department for International Development and its incorporation into a new <a href="https://www.gov.uk/government/organisations/foreign-commonwealth-development-office">Foreign, Commonwealth and Development Office</a> in <a href="https://www.devex.com/news/breaking-dfid-merged-with-fco-97489">2020</a>, as well as subverting aid to British self-interest, led to the departure of many experienced personnel who maintained the relationships with African political and civil society leaders. </p>
<p>It also removed a key ally for Africa within UK debates. Recent discussions around Africa have focused removing some migrants <a href="https://www.bbc.co.uk/news/explainers-61782866">to Rwanda</a>, hardly the bedrock of a high-level relationship. </p>
<p>And it’s hard to imagine former governments remaining silent over the Ethiopia crisis, for example, as the most recent Conservative administration has done.</p>
<h2>Truss offers little prospect of change</h2>
<p>Before her elevation to prime minister, Truss was the foreign, Commonwealth and <a href="https://www.theguardian.com/politics/2022/jul/28/foreign-office-not-regained-global-footing-under-liz-truss-report-finds">development office minister</a>. She showed little interest in development, anti-poverty policies or creating relationships based on mutual respect and dialogue. In fact, in my view, she contributed to the subversion of UK aid to British diplomatic and economic self-interest.</p>
<p>Her global tours as minister did not include a visit to Africa. </p>
<p>It is true that agreements have been signed with the Southern African Customs Union and Mozambique <a href="https://www.reuters.com/article/uk-britain-africa-trade-idUKKCN1VW1N5">in 2019</a>. But they offer little consolation in place of a new and powerful friendship.</p>
<p>More importantly, UK politics, and the attention of the new prime minister, will be firmly fixed on the domestic cost of living and inflation crisis, on a potential new row with the UK’s European Union neighbours (one of the UK government’s own making), and the conflict in Ukraine. Next on the agenda will be China, and the pursuit of trade deals elsewhere in the world.</p>
<p>It’s unlikely Britain’s limited attention span will have much space left for African issues and policy.</p>
<p>There is an argument to be made that African issues might receive a listening ear within the government given that most senior offices of state will, for the first time, be led by ministers with African heritage. The new chancellor is <a href="https://www.gov.uk/government/people/kwasi-kwarteng">Kwazi Kwarteng</a>, whose parents migrated from Ghana in the 1960s, and who has written a (mildly critical) <a href="https://www.nytimes.com/2012/03/04/books/review/ghosts-of-empire-by-kwasi-kwarteng.html">book</a> on the history of the British empire;
the Foreign, Commonwealth and Development Office will be led by <a href="https://www.gov.uk/government/people/james-cleverly">James Cleverly</a>, who has a Sierra Leonian mother; and the parents of the new Home Office minister, <a href="https://www.gov.uk/government/people/braverman">Suella Braverman</a>, came to Britain from Kenya and Mauritius. </p>
<p>Never before have the top posts been held by so many with direct links to Africa.</p>
<p>In my view, however, this is unlikely to make any real difference. None of the ministers have a strong record of advocating for closer or deeper ties with the continent. And despite Kwarteng’s criticism of the legacy of British colonial occupation, all three have signed up to the Conservative Party culture wars which see criticism of a glorious British past as treasonous wokery.</p>
<h2>Danger ahead</h2>
<p>There is a real danger that Britain will institute policies that actively harm African countries. Restoring UK aid to previous levels is becoming a vanishingly small possibility, which means cuts to vital social welfare programmes for some of the world’s most vulnerable communities. </p>
<p>Calls for renewed investment in fossil fuel production, and the possibility of backtracking on climate emission promises <a href="https://www.theguardian.com/environment/2022/sep/07/will-liz-trusss-government-adopt-or-weaken-green-policies">in response to the energy price crisis</a>, will undermine efforts to reduce the impact of the climate emergency.</p>
<p>African leaders and civil society organisations hoping a new broom will lead to a new set of relationships look set to be disappointed. Britain’s political myopia and navel-gazing will continue, with global engagement framed as something strictly to be done where it benefits the UK. Africa will likely have to wait for a new government, and a revived Department for International Development, for strong and close relations to be restored.</p><img src="https://counter.theconversation.com/content/190451/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Jennings is affiliated with the Fabian Society </span></em></p>Since the Brexit referendum in 2016, Africa has slipped from its precarious but tangible place in UK political discourse.Michael Jennings, Professor in Global Development, SOAS, University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1751162022-01-21T13:10:06Z2022-01-21T13:10:06ZShort-sightedness is on the rise in both children and adults – new study<figure><img src="https://images.theconversation.com/files/441959/original/file-20220121-15-1u5hv5t.jpg?ixlib=rb-1.1.0&rect=23%2C0%2C3891%2C2617&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Short-sightedness is increasing worldwide. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/shortsighted-woman-holding-glasses-hand-white-1699397968">chali_studio/ Shutterstock</a></span></figcaption></figure><p>We’ve known for years now that <a href="https://www.nature.com/articles/519276a">rates of short-sightedness</a> (scientifically known as myopia) are rising globally. Some estimates even suggest that <a href="https://www.aaojournal.org/article/s0161-6420(16)00025-7/fulltext">half of the world’s population</a> will be short-sighted by 2050. In the UK and Europe alone, rates of short-sightedness have <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0146332">doubled in the last 50 years</a>. </p>
<p>But we still aren’t completely sure why these rates are rising so significantly – and who might be most at risk. This is what a recent study set out to understand. Looking at data from 107,442 participants aged 40-69, the researchers confirmed that rates of myopia have <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0260993">increased significantly</a> in the UK in all age groups – and showed that education level and ethnicity may also be linked to greater risk.</p>
<p>They found that there was a jump in the number of people with short-sightedness when they compared participants born between 1965-1970 with those born between 1939-1944 – going from 20% of the population having myopia to nearly 30%. They also found that a greater number of people were developing short-sightedness in adulthood. Those who developed short-sightedness in childhood were also shown to become highly short-sighted and at greater risk of developing <a href="https://www.sciencedirect.com/science/article/pii/S1350946212000444?via%3Dihub">serious eye conditions</a> in adulthood.</p>
<p>To get a better picture of whether certain groups were more at risk than others, the researchers compared participants by sex, ethnicity and education level.</p>
<p>While previous studies have found that women are <a href="https://iovs.arvojournals.org/article.aspx?articleid=2775369">more short-sighted on average</a> – particularly at <a href="https://iovs.arvojournals.org/article.aspx?articleid=2776744">younger ages</a> – others have <a href="https://pubmed.ncbi.nlm.nih.gov/10416931/">found no difference</a> between men and women. </p>
<p>This study found women had a 24% increased risk of developing myopia in childhood – but were 12% less likely to develop myopia in adulthood. It’s uncertain why this is – but it might be due to differences in lifestyle or the hormonal changes men and women experience. </p>
<p>Looking then at ethnicity, the researchers found that there was a higher prevalence of myopia in people who were Chinese. In fact, Chinese participants had a 240% greater risk of developing short-sightedness in childhood compared to white participants. Interestingly, all other ethnicities appeared to have a reduced risk of developing myopia in childhood – though this might be due to the fact that UK Biobank data has <a href="https://biobank.ctsu.ox.ac.uk/crystal/field.cgi?id=21000">fewer participants from ethnic minority backgrounds</a>.</p>
<p>These findings relate to what previous studies have shown, with research suggesting there’s a greater prevalence of <a href="https://pubmed.ncbi.nlm.nih.gov/28951126/">myopia in east Asia</a> and in people of <a href="https://pubmed.ncbi.nlm.nih.gov/23672971/">Asian descent</a>. One study looking at young men in Seoul found that almost <a href="https://iovs.arvojournals.org/article.aspx?articleid=2166142">97% of 19-year-olds were myopic</a>. Again, it’s not certain why this group has higher rates of short-sightedness. Some theorise it could be caused by <a href="https://iovs.arvojournals.org/article.aspx?articleid=2727314">lifestyle factors during childhood</a>, such as greater focus on education. </p>
<figure class="align-center ">
<img alt="University student with glasses reads his book." src="https://images.theconversation.com/files/441961/original/file-20220121-27-knp81v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/441961/original/file-20220121-27-knp81v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/441961/original/file-20220121-27-knp81v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/441961/original/file-20220121-27-knp81v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/441961/original/file-20220121-27-knp81v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/441961/original/file-20220121-27-knp81v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/441961/original/file-20220121-27-knp81v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Years in education was also linked to short-sightedness.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/focused-millennial-african-american-student-glasses-1079701271">fizkes/ Shutterstock</a></span>
</figcaption>
</figure>
<p>The researchers also looked at the impact that education had on short-sightedness. They found that the more years spent in education, the greater the risk a person had of developing short-sightedness in both childhood and adulthood. They also showed that the youngest participants (those born between 1965-1970) who had a university education were eight times more likely to develop myopia in childhood compared to those that had no formal education qualifications. Previous studies have also shown that people who spent more years in education are <a href="https://www.bmj.com/content/361/bmj.k2022.long">more likely to develop myopia</a>.</p>
<p>The nuanced relationship between ethnicity and education was also explored. Having no formal educational qualifications was linked with lower risk of becoming short-sighted, as expected. This was most visibly shown in Chinese participants, where having no qualifications did not change their risk of developing myopia. However, Chinese participants that had higher level qualifications (such as a University degree) had the largest risk of myopia across the whole study. </p>
<p>Although it’s clear that education has a large hand in the development of myopia, the direct cause is unknown. Some argue that <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0140419">more time spent reading</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/31943280/">using screens</a> may be to blame. There’s now evidence even suggesting a link between home-schooling during COVID-19 lockdowns and <a href="https://jamanetwork.com/journals/jama/fullarticle/2784348">greater amounts of myopia</a> in <a href="https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2774808">Chinese children</a> – potentially because more time is being spent indoors. </p>
<p>But the significant increase in short-sightedness is concerning for a number of reasons. For a person with myopia, having to wear glasses or contact lenses <a href="https://iovs.arvojournals.org/article.aspx?articleid=2127768">can be costly</a>. More significantly, it also puts them at greater risk of eye diseases – such as <a href="https://journals.lww.com/optvissci/FullText/2019/06000/Myopia_Control__Why_Each_Diopter_Matters.11.aspx">myopic maculopathy</a> and <a href="https://www.sciencedirect.com/science/article/pii/S1350946212000444?via%3Dihub">retinal detachments</a>, which can both permanently affect eyesight. Not only could this seriously impact a person’s way of life, it would also put a greater financial strain on healthcare systems. Short-sightedness in children is even more concerning, as they’re more likely to develop into severe myopia – which is more likely to lead to these eye problems as a result. </p>
<p>While you can’t change genetics – <a href="https://iovs.arvojournals.org/article.aspx?articleid=2727314">which is one of the causes of myopia </a> – there are a number of actions you can take to lower the risk of developing short-sightedness during childhood. Spending time outdoors has continued to demonstrate a protective effect against <a href="https://www.nature.com/articles/s41598-021-85825-y">developing short-sightedness</a>. But for children who may already be shortsighted, <a href="https://bjo.bmj.com/content/early/2021/03/17/bjophthalmol-2020-317664.info">specialised spectacles</a> and <a href="https://iovs.arvojournals.org/article.aspx?articleid=2727315">contact lenses</a> are available that have demonstrated success in reducing myopia progression.</p><img src="https://counter.theconversation.com/content/175116/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The study found 30% of adults born between 1965-1970 were short-sightedness.Neema Ghorbani Mojarrad, Lecturer in Optometry, University of BradfordSophie Coverdale, Optometrist and PhD Researcher, University of BradfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1718262021-11-25T04:21:36Z2021-11-25T04:21:36ZWhat is orthokeratology? And will it help slow the deterioration of my child’s eyesight?<figure><img src="https://images.theconversation.com/files/432109/original/file-20211116-21-1fbmxqn.jpg?ixlib=rb-1.1.0&rect=0%2C7%2C2443%2C1616&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>If you or your child is short-sighted (struggles to see things further away) you might have heard about orthokeratology. </p>
<p>Also known as OK or ortho-k, orthokeratology has been around since the 1960s. However, it has gained interest recently for its ability to slow the progression of myopia (short-sightedness).</p>
<p>Orthokeratology involves wearing a specially-designed rigid contact lens overnight. Like a mold, the lens temporarily reshapes the eye while you sleep by gently changing the profile of the cornea (the eye’s clear, protective outer layer that acts like a powerful lens).</p>
<p>This creates a temporary change; when you wake up, you take the lens off and voilà! You can see.</p>
<p>It takes about a week of going through the cycle for the full effect to be reached but after that – assuming you wear them every night and take them off every morning – you should be able to get through your days without glasses or contact lenses. </p>
<p>And most importantly, there’s good evidence it can help slow the progression of myopia.</p>
<p>Like all treatments, however, orthokeratology has its pros and cons – and its risks need to be well understood before use. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/hidden-in-plain-sight-how-the-covid-19-pandemic-is-damaging-childrens-vision-158737">Hidden in plain sight: How the COVID-19 pandemic is damaging children’s vision</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/432114/original/file-20211116-25-1tk03qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/432114/original/file-20211116-25-1tk03qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/432114/original/file-20211116-25-1tk03qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432114/original/file-20211116-25-1tk03qz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432114/original/file-20211116-25-1tk03qz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432114/original/file-20211116-25-1tk03qz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432114/original/file-20211116-25-1tk03qz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432114/original/file-20211116-25-1tk03qz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The orthokeratology lens temporarily reshapes the eye while you sleep.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>The pros</h2>
<p>Orthokeratology may be an appealing option:</p>
<ul>
<li><p>for people who want an alternative to glasses but find contact lenses either uncomfortable or not suitable (because, for example, they suffer from <a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/dry-eye">dry eye</a>, work in dusty environments or enjoy water sports)</p></li>
<li><p>as an alternative to refractive surgery, also known as laser eye surgery or LASIK. Refractive surgery is permanent but orthokeratology is temporary; if you stop using the lenses, things go back to normal within a week</p></li>
<li><p>for parents of a child who might otherwise be wearing contact lenses at school; ortho-k allows a child to go to school without glasses or contact lenses, which can be lost or come loose during the day.</p></li>
</ul>
<h2>The cons</h2>
<p>The potential downsides include:</p>
<ul>
<li><p>the up-front costs are higher than daily wear contact lenses where the similar overall cost is spread over time</p></li>
<li><p>the effect wears off if you don’t use them every night</p></li>
<li><p>all contact lens use comes with a higher risk of eye infection than if you had no contact lenses at all.</p></li>
</ul>
<p>Some people might think orthokeratology has a higher infection risk than standard soft contact lenses. However, this is not supported by the research evidence. </p>
<p>A <a href="https://onlinelibrary.wiley.com/doi/10.1111/opo.12460">study in Japan</a> compared outcomes after 10 years of wear in children of either orthokeratology or soft contact lenses. It found there were no severe adverse events and the frequency of mild and adverse events were about equal between the groups. </p>
<p>If you get an infection from either a standard contact lens or orthokeratology lenses, it usually clears up with a course of antibiotics. However, it’s possible to get a rare infection called microbial keratitis, which has the potential to damage sight.</p>
<p>It’s not common. According to one <a href="https://journals.lww.com/optvissci/Abstract/2013/09000/The_Risk_of_Microbial_Keratitis_With_Overnight.6.aspx">study</a>, if you were to wear an orthokeratology lens every night for 1,000 years you are only likely to get one serious infection. </p>
<p>If you use sterile contact lens solutions and avoid tap water, orthokeratology lens-wearers will dramatically reduce their risk of eye infection. Tap water exposure to lenses or lens accessories greatly <a href="https://iovs.arvojournals.org/article.aspx?articleid=2124094">increases the risk of infection</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/432111/original/file-20211116-25-1fqf1ts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A girl gets her eyes tested." src="https://images.theconversation.com/files/432111/original/file-20211116-25-1fqf1ts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/432111/original/file-20211116-25-1fqf1ts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432111/original/file-20211116-25-1fqf1ts.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432111/original/file-20211116-25-1fqf1ts.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432111/original/file-20211116-25-1fqf1ts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432111/original/file-20211116-25-1fqf1ts.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432111/original/file-20211116-25-1fqf1ts.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Slower myopia progression also means less frequent need for replacing glasses, which can save you money in the long run.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Reducing risk of devasting eye disease later in life</h2>
<p>It’s now projected <a href="https://www.aaojournal.org/article/S0161-6420(16)00025-7/fulltext">half the world’s population will by myopic by 2050</a>, and the World Health Organization has sounded the alarm, saying in one <a href="https://www.who.int/bulletin/volumes/98/6/19-240903.pdf">bulletin</a>:</p>
<blockquote>
<p>High myopia greatly increases the risk of macular atrophy, glaucoma and
other causes of severe vision loss, the incidence of which is not reduced by
wearing standard glasses.</p>
</blockquote>
<p>Slowing the progression of myopia reduces <a href="https://theconversation.com/hidden-in-plain-sight-how-the-covid-19-pandemic-is-damaging-childrens-vision-158737">risk of sight-threatening eye disease</a>. It also means less frequent changes in vision, which can save money in the long run from needing fewer changes to glasses.</p>
<p>Myopia progresses <a href="https://journals.lww.com/optvissci/Abstract/2012/01000/Myopia_Progression_Rates_in_Urban_Children_Wearing.7.aspx">faster in younger years</a>, so a myopia control prevention should be prescribed as early as possible. We don’t know exactly how orthokeratology slows myopia progression, but compelling <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0124535">research</a> shows it does.</p>
<p>If you’re considering orthokeratology for your child, you and your eye specialist need to strike a balance. The child must be old enough to be handle it – but wait too long and the the myopia control benefits it offers diminish. </p>
<p>Every child is different. Some are more able than others to contend with orthokeratology, or willing to wear it overnight. It can be uncomfortable at first, and some might find the idea of a contact lens too confronting. It cannot be forced.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/432113/original/file-20211116-13-1j6celv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/432113/original/file-20211116-13-1j6celv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/432113/original/file-20211116-13-1j6celv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432113/original/file-20211116-13-1j6celv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432113/original/file-20211116-13-1j6celv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432113/original/file-20211116-13-1j6celv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432113/original/file-20211116-13-1j6celv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432113/original/file-20211116-13-1j6celv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Too much ‘close work’ can make myopia worse in children.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Review all the options</h2>
<p>Orthokeratology isn’t the only solution; there are also special lenses you can get for glasses and soft daily wear contact lenses that help slow progression of myopia. Seek advice from eye specialists to to review all the options. </p>
<p>I also recommend children do no more than two hours per day of leisure “close work” (meaning non-school work: close up screen time or book-reading) outside school hours. Parents can also teach kids the “<a href="https://www.mykidsvision.org/blog/the-visual-environment/">20-20 rule</a>” (for every 20 minutes of close work, take a 20 second break to look into the distance). Outside time (<a href="https://www.mdpi.com/1660-4601/16/14/2595">two or more hours per day</a>) is also crucial to healthy eye development in children.</p>
<p>What’s clear, however, is that all short-sighted children should be doing something to control their myopia. It’s not enough just to give a child standard single vision glasses to help them see, without doing more to help slow the march of myopia.</p>
<p>If right for your child, orthokeratology has one of the strongest research pedigrees for slowing progression of myopia.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-keep-your-contact-lenses-clean-and-what-can-go-wrong-if-you-dont-141117">How to keep your contact lenses clean (and what can go wrong if you don't)</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/171826/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Gifford is an Adjunct Senior Lecturer at the University of New South Wales and Adjunct Associate Professor at the University of Waterloo, Canada. He is co-founder of Myopia Profile, which educates optometrists and companies on research relating to vision, and MyKidsVision.org which provides parent focused research backed information on managing childhood myopia.</span></em></p>Orthokeratology involves wearing a specially designed rigid contact lens overnight. There’s good evidence it can help slow the progression of myopia. But like all treatments, there are risks, too.Paul Gifford, Adjunct Senior Lecturer, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1623082021-06-16T10:21:16Z2021-06-16T10:21:16ZShort-sightedness is increasing in children – and researchers are still trying to understand why<figure><img src="https://images.theconversation.com/files/406519/original/file-20210615-15-7pq17y.jpg?ixlib=rb-1.1.0&rect=0%2C26%2C6000%2C3961&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Myopia is usually a lifelong condition.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/asian-child-kid-girl-wear-eye-1214506771">kornnphoto/ Shutterstock</a></span></figcaption></figure><p>Myopia is <a href="https://www.nytimes.com/2021/05/03/well/live/nearsightedness-myopia-children.html">on the rise</a>. In the UK, the number of children with myopia has <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0146332">doubled in the last 50 years</a>. Globally, it’s projected that by 2050 <a href="https://doi.org/10.1016/j.ophtha.2016.01.006">half of the world’s population</a> will be myopic.</p>
<p>Although myopia – also known as near-sightedness or short-sightedness – can <a href="https://iovs.arvojournals.org/article.aspx?articleid=2727314">run in families</a>, environmental factors, such as spending too much time indoors have a large influence. For most people, myopia develops from a mixture of both genetics and environmental factors. But while evidence shows that modern lifestyle factors contribute to myopia, scientists still aren’t entirely sure why. </p>
<p>For instance, research shows that the amount of time a child spends outdoors can play a significant role in their <a href="https://iovs.arvojournals.org/article.aspx?articleid=2727315">risk of developing myopia</a>. Not only do most studies show that children who <a href="https://iovs.arvojournals.org/article.aspx?articleid=2727315">spend more time outdoors</a> are less likely to develop myopia, studies requiring children to spend extra time outdoors during school hours have shown the <a href="https://iovs.arvojournals.org/article.aspx?articleid=2727315">rate of myopia onset decreased</a> compared with children who didn’t spend additional time outdoors.</p>
<p>But researchers still aren’t quite sure <a href="https://iovs.arvojournals.org/article.aspx?articleid=2772539#247195256">why this is the case</a>. <a href="https://link.springer.com/chapter/10.1007/978-981-13-8491-2_4">One theory</a> is that the higher levels of light outdoors releases more dopamine into our retinal receptors (the nerves that process light signals in the eye), <a href="https://iovs.arvojournals.org/article.aspx?articleid=2727313">thus protecting against myopia</a>. Another suggestion is that the greater amount of physical activity children typically get outdoors prevents myopia. But studies have now shown that this has <a href="https://iovs.arvojournals.org/article.aspx?articleid=2127681">little</a> <a href="https://www.sciencedirect.com/science/article/pii/S0014483513001061">effect</a>.</p>
<figure class="align-center ">
<img alt="Group of children playing football outdoors in the summer." src="https://images.theconversation.com/files/406523/original/file-20210615-3839-xeqvbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406523/original/file-20210615-3839-xeqvbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=394&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406523/original/file-20210615-3839-xeqvbw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=394&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406523/original/file-20210615-3839-xeqvbw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=394&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406523/original/file-20210615-3839-xeqvbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=495&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406523/original/file-20210615-3839-xeqvbw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=495&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406523/original/file-20210615-3839-xeqvbw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=495&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It’s still unknown why more time outdoors is good for eyesight.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/group-happy-schoolchildren-playing-football-together-1913590756">Iakov Filimonov/ Shutterstock</a></span>
</figcaption>
</figure>
<p>It’s also been suggested that the different patterns and details we see in outdoor versus indoor spaces might explain the increase in myopia. For example, one study suggests that the abundance of <a href="https://iovs.arvojournals.org/article.aspx?articleid=2770840">plain features and walls</a> in indoor environments is to blame. This may also be why myopia tends to be <a href="https://www.tandfonline.com/doi/full/10.1080/09286586.2019.1659979">more common in urban areas</a>, however, more research is needed to understand this.</p>
<h2>Modern lifestyles</h2>
<p>Nevertheless, modern lifestyles often require us to spend a lot of our time indoors. For example, children are spending longer in formal education thanks to increases in school leaving age and more people pursuing higher education, which evidence suggests <a href="https://www.bmj.com/content/361/bmj.k2022">can cause myopia</a>. Yet what aspects of formalised education are causing increases in myopia is still unknown. Prolonged reading, learning at close distances, time spent indoors and increased screen use might all be to blame.</p>
<p>While one study suggests reading at a distance <a href="https://iovs.arvojournals.org/article.aspx?articleid=2125070">closer than 25cm</a> may be a risk for developing myopia, reading probably only has a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4618477/#:%7E:text=The%20findings%20from%20this%20meta,%2C%20than%20non%2Dmyopic%20children.">small effect</a> on developing myopia.</p>
<p>The effect of greater screen use on myopia in children also has <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/opo.12657">mixed results</a> – probably because estimating screen use and controlling it in a long-term experiment is difficult. Regardless, further research is needed to understand whether excessive screen use is to blame for higher rates of myopia, and why this is the case. </p>
<p>Given the risk factors for developing myopia, there are also concerns now that stay-at-home orders and home learning during the pandemic may have <a href="https://journals.lww.com/ijo/Fulltext/2020/68070/Will_COVID_19_pandemic_associated_lockdown.80.aspx">worsened children’s eyesight</a>. Although there has been no study yet looking at the effect on children in the UK, early results elsewhere suggest that the pandemic may cause more children to <a href="https://www.aaojournal.org/article/S0161-6420(21)00234-7/fulltext">develop myopia</a> – but it’s anticipated the <a href="https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2774808">effects will be small</a>. Whether the pandemic will have caused permanent increases in myopia is also yet to be seen.</p>
<p>Currently, the best advice for limiting the risk of developing myopia is to increase time spent outdoors, <a href="https://ep.bmj.com/content/101/4/219">even by 40 minutes a day</a>.</p><img src="https://counter.theconversation.com/content/162308/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Neema Ghorbani Mojarrad does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Researchers are still uncovering how modern lifestyles may be causing this increase.Neema Ghorbani Mojarrad, Lecturer in Optometry, University of BradfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1587372021-04-27T21:53:28Z2021-04-27T21:53:28ZHidden in plain sight: How the COVID-19 pandemic is damaging children’s vision<figure><img src="https://images.theconversation.com/files/395775/original/file-20210419-23-swymch.jpg?ixlib=rb-1.1.0&rect=17%2C0%2C1279%2C746&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Children’s increased screen time, exacerbated by remote learning during COVID-19, is directly contributing to increases in childhood myopia.</span> <span class="attribution"><span class="source">(iStock)</span></span></figcaption></figure><p>Eye doctors had planned to celebrate 2020 as the year of vision (as in seeing 20/20). Instead, it will be known as the year that worsened the world’s vision for decades to come. Scientists are attributing this latest health issue — one that is hidden in plain sight — to the pandemic.</p>
<p>Rates of myopia, also known as nearsightedness or shortsightedness, have been increasing worldwide for decades. Half of the world’s population is <a href="https://doi.org/10.1016/j.ophtha.2016.01.006">predicted to be myopic by 2050</a>.</p>
<p>The length of time children spend viewing digital screens has been exacerbated by a massive increase in remote schooling, directly contributing to further increases in childhood myopia. Home-schooled children of the COVID-19 era are at risk of becoming the visually compromised population of tomorrow.</p>
<p><a href="http://doi.org/10.1001/jamaophthalmol.2020.6239">A recent study</a> of more than 120,000 children in China demonstrated that six- to eight-year-olds who were in lockdown for the first six months of 2020 are more myopic than their counterparts from previous years. </p>
<h2>Myopia risks</h2>
<p>For a child with myopia, distance vision is blurry while near vision remains clear. In the past, the increase in myopia diagnoses from year to year was given little thought, since it was correctable with glasses or contact lenses. However, eye-care professionals now know that the younger a child becomes myopic, the higher their prescription may eventually become, and high prescriptions are bad news for eyes. </p>
<figure class="align-center ">
<img alt="Children sit behind desks in a classroom" src="https://images.theconversation.com/files/395815/original/file-20210419-23-1ubaqbf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/395815/original/file-20210419-23-1ubaqbf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395815/original/file-20210419-23-1ubaqbf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395815/original/file-20210419-23-1ubaqbf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395815/original/file-20210419-23-1ubaqbf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395815/original/file-20210419-23-1ubaqbf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395815/original/file-20210419-23-1ubaqbf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Children’s increasing digital screen time is directly contributing to increases in childhood myopia.</span>
<span class="attribution"><span class="source">(iStock)</span></span>
</figcaption>
</figure>
<p>There is an established link between high myopia and <a href="http://doi.org/10.1016/j.preteyeres.2012.06.004">increased lifelong risk of devastating eye diseases</a>. Someone who has a prescription of more than six corrective units, or dioptres, (a prescription of -6.00) has a 90 per cent likelihood of being <a href="http://doi.org/10.1001/jamaophthalmol.2016.4009">visually impaired</a> by the age of 75.</p>
<p>A number of eye conditions are more prevalent in highly myopic adults including cataract, glaucoma, retinal detachment, retinal degeneration and other ocular diseases that can have a lifelong impact on their vision. These complications typically happen in later life, so concern for children may seem irrelevant or premature. However, there are other more immediate effects of high prescriptions. </p>
<p>A child or teenager with a fairly high prescription will be visually debilitated when not wearing their glasses or contacts, making them totally dependent on their vision correction. As an example, someone who has 10 dioptres of myopia sees anything beyond half an arm’s length as blurred. And don’t think that laser vision correction will save the day once they’re old enough. That degree of myopia may leave them <a href="https://www.webmd.com/eye-health/news/20191220/twenty-years-later-lasik-has-its-pros-and-cons">ineligible or subject to a less successful outcome</a>.</p>
<h2>Screen time</h2>
<p>The question then turns to what causes myopia in the first place, and what can be done about its onset and progression.</p>
<p>The biggest factor that can’t be changed is <a href="https://doi.org/10.1016/j.ajo.2020.05.026">parental myopia</a>. A child is extremely likely to become myopic if both parents are myopic. </p>
<p>One factor that is modifiable is the amount of time children spend on “near tasks,” those that involve viewing things closer than 40 centimetres from their eyes. </p>
<p>Extended periods of time spent focused on short distances is contributing to myopia increases. Digital screens have been targeted as the reason, but is it the electronic display itself or that a child holds a tablet or phone very close for extended periods? While there is some debate, <a href="https://dx.doi.org/10.1371%2Fjournal.pone.0134514">the short focusing distance</a> is the more likely culprit. </p>
<p>Even with the digital onslaught, all is not lost. Parents and caregivers can help prevent children from becoming nearsighted and slow down the rate at which the condition progresses.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/395819/original/file-20210419-17-j0ckyn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="infographic about myopia prevention" src="https://images.theconversation.com/files/395819/original/file-20210419-17-j0ckyn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/395819/original/file-20210419-17-j0ckyn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=423&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395819/original/file-20210419-17-j0ckyn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=423&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395819/original/file-20210419-17-j0ckyn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=423&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395819/original/file-20210419-17-j0ckyn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=532&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395819/original/file-20210419-17-j0ckyn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=532&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395819/original/file-20210419-17-j0ckyn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=532&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Protecting children from myopia.</span>
</figcaption>
</figure>
<p>Simply <a href="https://dx.doi.org/10.1111%2Faos.13403">spending more time outside</a> can delay the onset of myopia. Direct sunlight plays a part, as well as the long-range focusing while playing outdoors. Restricting screen time is an option with optometrist-endorsed <a href="https://opto.ca/sites/default/files/resources/documents/childrens_vision_and_screen_time_en_march_2018_0.pdf">recommendations relating to screen times for children</a>. </p>
<p>For children schooled at home where limits are not practical, ensure that the screen is not being held or positioned too close to a child, encourage regular breaks and use the 20-20-20 rule: look 20 feet (seven metres) away every 20 minutes for 20 seconds. Some researchers have found that children who <a href="https://bhvi.org/news/sleeping-late-is-a-risk-factor-for-myopia-development-amongst-school-aged-children-in-china/">go to bed later</a> are more likely to be myopic — an added incentive for parents who are looking for reasons to call it a night.</p>
<p>A child’s myopia usually continues to progress until around the age of 16, but <a href="https://doi.org/10.1167/iovs.13-12403">about 10 per cent of myopic patients’</a> vision keeps worsening into their early 20s. </p>
<h2>Treatment and prevention</h2>
<p>Many options exist for vision correction, but more importantly, <a href="https://reviewofmm.com/current-treatments-in-myopia-management/">there are an increasing number</a> of options available to slow down the progression of myopia and <a href="https://doi.org/10.1097/opx.0000000000001367">reduce the risk</a> of developing sight-threatening complications in later life. They range from contact lenses and glasses specifically designed to slow down myopia progression to precisely formulated eye drops. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/395822/original/file-20210419-17-1l1totu.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="infographic about slowing myopia progression" src="https://images.theconversation.com/files/395822/original/file-20210419-17-1l1totu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/395822/original/file-20210419-17-1l1totu.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=750&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395822/original/file-20210419-17-1l1totu.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=750&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395822/original/file-20210419-17-1l1totu.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=750&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395822/original/file-20210419-17-1l1totu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=943&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395822/original/file-20210419-17-1l1totu.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=943&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395822/original/file-20210419-17-1l1totu.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=943&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ways to slow myopia progression in kids.</span>
<span class="attribution"><span class="source">(Alison Ng, CORE University of Waterloo)</span></span>
</figcaption>
</figure>
<p>These can be discussed with your eye-care practitioner, who will recommend the best path based on each child.</p>
<p>More than anything else, do not assume a child can see well. There is no substitution for an examination with an eye-care professional. The pandemic has already caused widespread hardship. By acting now, parents can minimize its impact on the vision and ocular health of generations to come.</p><img src="https://counter.theconversation.com/content/158737/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The COVID-19 pandemic has resulted in children spending more time on digital devices, which may have a long-term impact on their vision, including the risk of myopia.Debbie Jones, Clinical Professor, School of Optometry & Vision Science and Clinical Scientist, Centre for Ocular Research & Education (CORE), University of WaterlooKate Gifford, Visiting Research Fellow in Optometry and Vision Science, Queensland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1558632021-03-07T14:36:27Z2021-03-07T14:36:27ZWhy you shouldn’t neglect eye care during the COVID-19 pandemic<figure><img src="https://images.theconversation.com/files/387366/original/file-20210302-15-11edc9e.jpg?ixlib=rb-1.1.0&rect=20%2C20%2C2294%2C1535&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">One-third of adults report deriorating eyesight since the pandemic began.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/aVvZJC0ynBQ">(Unsplash/David Travis)</a></span></figcaption></figure><p>Since COVID-19 emerged, access to eye care has continued to change. Lockdowns and concerns about virus exposure have caused people of all ages to cancel and delay routine appointments, raising red flags among eye-care professionals. As the pandemic continues into its second year, can ocular health be neglected any longer?</p>
<p>Our team of optometrists and clinical scientists at the <a href="https://core.uwaterloo.ca/">Centre for Ocular Research & Education</a> (CORE) hear the confusion and concerns about people’s eyes during COVID-19. Addressing the most common questions — many of which we keep up to date at <a href="https://covideyefacts.org/">COVIDeyefacts.org</a> — can help you and your family maintain the best vision while staying safe.</p>
<h2>Can I set aside my eye health?</h2>
<p>A survey commissioned by <a href="https://www.fightforsight.org.uk">Fight for Sight</a>, a charity in the United Kingdom devoted to eye research, reveals that <a href="https://www.fightforsight.org.uk/news-and-articles/articles/news/screen-time/">one in five adults in the U.K.</a> are less likely to visit an eye doctor during the pandemic. This is despite finding that one-third of adults have reported deteriorating eyesight since the pandemic began.</p>
<p>Thousands of patients who previously sought regular treatment for chronic, sight-threatening eye conditions are <a href="https://www.bbc.com/news/health-52968845">missing vital appointments</a> that help to preserve their vision. </p>
<p><a href="https://doi.org/10.2147/OPTH.S267950">Ophthalmologists report</a> that patients with retinal conditions such as macular degeneration and diabetic retinopathy are skipping hospital appointments for sight-preserving injections, which often leads to <a href="https://doi.org/10.2147/OPTH.S296345">devastating consequences such as disease progression</a>, giving rise to significant <a href="https://doi.org/10.1016/j.oret.2020.12.020">vision loss</a>.</p>
<h2>What eye conditions cannot wait?</h2>
<p>Putting aside COVID-19 concerns, there are seven reasons to urgently call your eye doctor, no matter the age of the patient:</p>
<ul>
<li><p>Eye injury</p></li>
<li><p>Eye pain</p></li>
<li><p>If you notice new floaters or flashes of light</p></li>
<li><p>Red eye</p></li>
<li><p>A sudden change in vision</p></li>
<li><p>Blank or wavy spots</p></li>
<li><p>Refills for prescription drops</p></li>
</ul>
<p>Delaying care in these situations may result in poor outcomes, including vision loss. Some clinics offer telephone consultations to triage care and discuss options. When in doubt, call.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/387361/original/file-20210302-13-cuw69r.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Infographic summarizing 7 reasons to urgently contact your eye doctor" src="https://images.theconversation.com/files/387361/original/file-20210302-13-cuw69r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/387361/original/file-20210302-13-cuw69r.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/387361/original/file-20210302-13-cuw69r.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/387361/original/file-20210302-13-cuw69r.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/387361/original/file-20210302-13-cuw69r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/387361/original/file-20210302-13-cuw69r.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/387361/original/file-20210302-13-cuw69r.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Infographic summarizing seven reasons to urgently contact your eye doctor.</span>
<span class="attribution"><span class="source">(Alison Ng/CORE, University of Waterloo)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Have eye exams changed?</h2>
<p>As with every aspect of our lives, significant modifications have been made to the way eye-care professionals and clinics are operating, putting safety first. You will see spaced appointments and physical distancing, staff and doctors using protective equipment, modifications to some tests, accommodations for ventilation and more — with the same commitment to patient health.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/387362/original/file-20210302-13-1pntb0y.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Infographic summarizing 7 key things to expect when getting an eye exam during the COVID-19 pandemic" src="https://images.theconversation.com/files/387362/original/file-20210302-13-1pntb0y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/387362/original/file-20210302-13-1pntb0y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1500&fit=crop&dpr=1 600w, https://images.theconversation.com/files/387362/original/file-20210302-13-1pntb0y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1500&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/387362/original/file-20210302-13-1pntb0y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1500&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/387362/original/file-20210302-13-1pntb0y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1885&fit=crop&dpr=1 754w, https://images.theconversation.com/files/387362/original/file-20210302-13-1pntb0y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1885&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/387362/original/file-20210302-13-1pntb0y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1885&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Eye care professionals have put safety measures in place to help prevent the spread of COVID-19. Here’s what to expect at an eye exam during the pandemic.</span>
<span class="attribution"><span class="source">(Alison Ng/CORE, University of Waterloo)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Do I really need to have an exam?</h2>
<p>When your eye doctor is shining those bright lights into your eyes, they are checking for signs that might point to painless and progressive diseases that may not be apparent.</p>
<p>For example, glaucoma affects the optic nerve, causing gradual irreversible vision loss. It is the <a href="https://www.glaucoma.org/glaucoma/glaucoma-facts-and-stats.php">leading cause of irreversible blindness</a> globally and more than 80 per cent of those affected experience silent vision loss. Often, patients with glaucoma fail to notice any symptoms until 40 per cent of nerve damage has occurred. Early detection and timely treatment limits further damage.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/387364/original/file-20210302-23-j5i7xy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Eye doctor wearing a face mask, goggles and gloves, performing an eye exam with a patient." src="https://images.theconversation.com/files/387364/original/file-20210302-23-j5i7xy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/387364/original/file-20210302-23-j5i7xy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/387364/original/file-20210302-23-j5i7xy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/387364/original/file-20210302-23-j5i7xy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/387364/original/file-20210302-23-j5i7xy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/387364/original/file-20210302-23-j5i7xy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/387364/original/file-20210302-23-j5i7xy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An eye doctor examining the eyes of a patient. The eye doctor is wearing personal protective equipment including a face mask, goggles and gloves. There is a plastic breath shield between the eye doctor and the patient, and the patient is also wearing a face mask.</span>
<span class="attribution"><span class="source">(CORE, University of Waterloo)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Can I trust online sources for care information?</h2>
<p>Let’s say you wake up with red eyes. Dr. Google will likely tell you that you have conjunctivitis, or pink eye — a simple eye infection that disappears without consequences. However, increased eye redness is not only caused by pink eye. This is referred to as a “differential diagnosis” or “what else could this be?”</p>
<p>For example, inflammation of the iris also presents as a red eye. Without timely treatment involving prescription eye drops, this condition progresses to worsening pain, light sensitivity, blurred vision and can lead to cataracts, glaucoma or permanent vision loss. The only way to confirm the cause of an eye problem and get appropriate treatment is to see an eye care professional.</p>
<h2>What about the kids?</h2>
<p>With estimates that <a href="https://doi.org/10.1016/j.ophtha.2016.01.006">half of the world’s population will be myopic (nearsighted) by 2050</a> and the time that <a href="https://www.nytimes.com/2021/01/16/health/covid-kids-tech-use.html">kids spend on screens skyrocketing</a>, the <a href="https://www.thestar.com/local-brampton/news/2021/01/18/learning-at-home-parents-optometrists-concerned-about-long-lasting-effects-of-increased-screen-time.html">impact on their vision</a> might be around <a href="https://doi.org/10.1001/jamaophthalmol.2020.6239">long after this pandemic is over</a>. </p>
<p><a href="https://doi.org/10.1038/s41433-018-0015-5">A CORE study found</a> almost one-third of Canadian school children aged 11 to 13 were myopic, and 35 per cent of myopic children did not have glasses or contact lenses to help them see better. Some children simply do not know they have an eye problem, because they assume that everyone sees the same.</p>
<h2>Is it safe to get an eye exam?</h2>
<p>Every effort is being made to ensure that staff, doctors and patients are kept safe. Clinic personnel are expected to stay home and isolate if they have symptoms of COVID-19 in the same way that patients are. </p>
<p>In a time of continued uncertainty, one thing remains clear: your vision is important and you can take steps to keep it that way, even during a pandemic.</p><img src="https://counter.theconversation.com/content/155863/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Over the past 3 years, Alison Ng and the research group (CORE) has received research support or lectureship honoraria from Alcon, Allergan, Allied Innovations, Aurinia Pharma, BHVI, CooperVision, GL Chemtec, i-Med Pharma, Johnson & Johnson Vision, Lubris, Menicon , Nature’s Way, Novartis, Ophtecs, Oté Pharma, PS Therapy, Santen, Shire, SightGlass, SightSage and Visioneering. She is also a Tear Film and Ocular Surface Society (TFOS) Ambassador for Canada. </span></em></p><p class="fine-print"><em><span>Over the past 3 years, Mike Yang and the research group (CORE) has received research support or lectureship honoraria from Alcon, Allergan, Allied Innovations, Aurinia Pharma, BHVI, CooperVision, GL Chemtec, i-Med Pharma, Johnson & Johnson Vision, Lubris, Menicon , Nature’s Way, Novartis, Ophtecs, Oté Pharma, PS Therapy, Santen, Shire, SightGlass, SightSage and Visioneering.</span></em></p>The COVID-19 pandemic has caused people of all ages to cancel or delay routine eye care, raising red flags among eye care professionals.Alison Ng, Clinical Scientist at the Centre for Ocular Research & Education (CORE), University of WaterlooMike Yang, Clinical Scientist at Centre for Ocular Research & Education, University of WaterlooLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1463512020-09-16T16:51:20Z2020-09-16T16:51:20ZDoes wearing glasses protect you from coronavirus?<figure><img src="https://images.theconversation.com/files/358438/original/file-20200916-22-9cjnms.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5122%2C3412&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/attractive-beautiful-positive-asian-man-close-720702637">paulaphoto/Shutterstock</a></span></figcaption></figure><p>Researchers in China have found that people who wear glasses appear to be at lower risk of catching COVID-19. The authors of the study, <a href="https://jamanetwork.com/journals/jamaophthalmology/fullarticle/2770872">published in JAMA Ophthalmology</a>, noticed that since the coronavirus outbreak in Wuhan in December 2019, few patients with spectacles were admitted to hospital suffering from COVID-19. To investigate further, they collected data on the wearing of glasses from all patients with COVID-19 as part of their medical history.</p>
<p>Their small study found that only 16 (5.8%) of the 276 patients admitted with COVID-19 wore glasses for more than eight hours a day. As they determined that all these patients were short-sighted, they next looked up the proportion of people with myopia (short-sightedness) in Hubei Province, where the hospital is located. They found this to be much larger (31.5%), indicating that the proportion of short-sighted COVID-19 hospital admissions was over five times lower than might be expected from that population.</p>
<p>This is a fascinating observation, but as with all single studies the results must be treated with caution. While eye protection <a href="https://www.cdc.gov/niosh/topics/eye/eye-infectious.html">has always been</a> an important component of personal protective equipment (PPE), the magnitude of difference reported by this study raises suspicion. This is not to say that the results may not be real, but rather that we shouldn’t start advising large-scale behavioural changes (such as wearing goggles alongside our face masks) until they have been independently confirmed.</p>
<h2>Are eyes a window for the virus?</h2>
<p>One of the key steps for any viral infection is the initial entry into the body. While most of our body is covered with protective skin, which is very effective at preventing viruses or bacteria crossing into our body, far thinner “membranes” cover our airways, digestive system and eyes. The role of these thinner membranes is to allow external things such as oxygen, food, and in the case of eyes, light, into our bodies. Unfortunately, viruses have learned to take advantage of these entry points. </p>
<p>This is the reason PPE is designed to protect these entry points, through the use of face masks, goggles and protective clothing. However, whereas we might imagine that the main attack on these regions comes from viral particles transmitted through the air as aerosols, the main way that viral particles get to these weak points is actually via <a href="https://www.ncbi.nlm.nih.gov/books/NBK144014/">our hands</a>. Hence the COVID-19 advice to wash our hands often, for 20 seconds or more, and avoid touching our faces.</p>
<p>It therefore makes sense that covering our eyes with glasses may offer extra protection, both from the virus that may be carried in other people’s breath, but also in preventing wearers from touching their eyes. Indeed, as far back as February there <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30313-5/fulltext#articleInformation">were reports</a> of people catching COVID-19 by not suitably protecting their eyes in healthcare settings. It is also known that similar points of entry into the body (ACE-2 receptors) favoured by the coronavirus <a href="https://pubmed.ncbi.nlm.nih.gov/28761566/">are also present in the eyes</a>.</p>
<h2>Should we start wearing goggles?</h2>
<p>A critical part of interpreting any evidence coming from observational studies is remembering that correlation (two things happening together) does not necessarily mean causation (one thing causes the other). To test for causation, a controlled trial or test is now needed. </p>
<p>Ideally, this would follow two carefully matched groups of people – some wearing glasses and some not wearing glasses – to see which group gets infected more often. Evidence from such a controlled trial will always be far stronger than evidence from an observational study such as that in the recent paper.</p>
<p>We must also note that the authors of this study listed a number of weaknesses. It was a very small study at a single site. The researchers’ data for the general population came from a much earlier study on a sample that was not exactly matched (in terms of age, demography and other factors) to their sample admitted to hospital with COVID-19. And they couldn’t guarantee that all the people with short-sightedness in the general population also wore glasses for more than eight hours a day.</p>
<p>So although this new study is very interesting, there are plenty of reasons to be cautious about this result. We certainly need more data before any advice can be given about wearing goggles alongside our face masks.</p><img src="https://counter.theconversation.com/content/146351/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Kolstoe does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New study finds that glasses may help protect from catching coronavirus. But we need more evidence.Simon Kolstoe, Senior Lecturer in Evidence Based Healthcare and University Ethics Advisor, University of PortsmouthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1381932020-05-21T12:22:14Z2020-05-21T12:22:14ZIncreasing screen time during the coronavirus pandemic could be harmful to kids’ eyesight<figure><img src="https://images.theconversation.com/files/335514/original/file-20200516-138634-xtp6t0.jpg?ixlib=rb-1.1.0&rect=66%2C56%2C2066%2C1336&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">With online learning, children are staring at computer screens for more hours each day. </span> <span class="attribution"><a class="source" href="http://gettyimages.com">Christopher Furlong/Getty Images</a></span></figcaption></figure><p>The coronavirus pandemic is remaking the way children learn, and it could have an impact on their eyes. </p>
<p>With schools shifting to online lessons at home, children are spending more time in front of computer screens, and many parents are <a href="https://theconversation.com/forget-old-screen-time-rules-during-coronavirus-heres-what-you-should-focus-on-instead-135053">relaxing screen-time rules</a> for TV and video games to keep kids occupied while social distancing. In the midst of the crisis, many children are spending less time playing outdoors.</p>
<p>This combination – more screen time and less outdoor time – may actually harm children’s vision and put them at higher risk of developing myopia, or nearsightedness. That can lead to serious eye problems in the future, including some potentially blinding diseases.</p>
<p>As <a href="https://scholar.google.com/citations?user=DjdCWeYAAAAJ&hl=en">a health behavioral and policy professor</a> and <a href="https://medicine.umich.edu/dept/ophthalmology/olivia-killeen-md">an ophthalmology resident</a> interested in health promotion and eye care for children, we’re concerned about the impacts of decreased outdoor time and excess screen time on children’s eyes during the COVID-19 pandemic.</p>
<h2>What causes myopia?</h2>
<p>Scientists are still trying to understand how myopia, or nearsightedness, develops and progresses.</p>
<p>It occurs when the eyeball is too long or the eye’s focusing power is too strong, causing light rays to <a href="https://www.aao.org/eye-health/diseases/myopia-nearsightedness">focus in front of the retina</a> instead of on it, which creates a blurry image. While glasses or contact lenses can correct a child’s vision, research shows that having <a href="http://doi.org/10.1097/IAE.0000000000001489">severe myopia puts children at risk</a> for a number of eye problems down the road, including retinal detachment, glaucoma and macular degeneration.</p>
<p>Some factors in whether a child develops myopia, such as genetics, are beyond a parent’s control, but research shows that other risks can be reduced.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/336574/original/file-20200520-152298-ow2a1a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/336574/original/file-20200520-152298-ow2a1a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=675&fit=crop&dpr=1 600w, https://images.theconversation.com/files/336574/original/file-20200520-152298-ow2a1a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=675&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/336574/original/file-20200520-152298-ow2a1a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=675&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/336574/original/file-20200520-152298-ow2a1a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=848&fit=crop&dpr=1 754w, https://images.theconversation.com/files/336574/original/file-20200520-152298-ow2a1a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=848&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/336574/original/file-20200520-152298-ow2a1a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=848&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In people with myopia, light focuses in front of the retina rather than on it, so distant objects appear blurry.</span>
<span class="attribution"><span class="source">Anurag Papolu/The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>A review of <a href="http://doi.org/10.1371/journal.pone.0140419">25 years of research</a> found that working up close – like reading or using a tablet – increased the odds of myopia.</p>
<p>For example, a nationwide study in Taiwan found that after-school study programs with lots of closeup work were associated with an <a href="https://doi.org/10.1016/j.ophtha.2018.05.010">increased likelihood of nearsightedness</a> among children ages 7 to 12. A study of Chinese schoolchildren found that increased time spent working with the eyes focused on something <a href="http://dx.doi.org/10.1136/bjophthalmol-2019-315258">less than 20 centimeters away</a> was associated with myopia. Researchers in Ireland found that <a href="http://doi.org/10.1136/bjophthalmol-2018-313325">greater than three hours of screen time per day</a> increased the odds of myopia in schoolchildren, and investigators in Denmark found that the risk of myopia approximately doubled in <a href="https://doi.org/10.1111/aos.14242">Danish teenagers who used screen devices</a> for more than six hours per day.</p>
<h2>Getting outdoors matters</h2>
<p>Some studies now suggest that <a href="http://doi.org/10.1016/j.ophtha.2012.04.020">spending time outdoors</a> may be able to slow the onset and progression of nearsightedness.</p>
<p>In Taiwan, first grade students at schools with <a href="http://doi.org/10.1016/j.ophtha.2017.12.011">programs designed to increase their outdoors time</a> to 11 hours or more each week had less progression of myopia over one year compared to their peers. Similarly, in China, researchers found that <a href="http://doi.org/10.1001/jama.2015.10803">adding 40 minutes of outdoor activity</a> a day at school reduced the development of nearsightedness in six-year-old children over the next three years.</p>
<p>It is not clear why outdoors time protects against myopia, or why closeup work could make it worse. One theory is that <a href="http://doi.org/10.1038/s41588-018-0127-7">light intensity and time spent outdoors</a> regulates the <a href="https://doi.org/10.1016/j.exer.2006.09.018">release of dopamine in the retina</a>, which controls the growth of the eye. Other theories center on how <a href="https://www.ncbi.nlm.nih.gov/books/NBK470669/">viewing distances impact where the light is focused</a> on the retina; shorter viewing distances indoors may promote abnormal growth of the eye. </p>
<p>Although there is no consensus on how much time children need to spend outside or the importance of the light intensity they are exposed to, it is possible that more outdoor time can help to balance out more closeup work, as a <a href="http://doi.org/10.1016/j.ophtha.2007.12.019">study of children in Australia found</a>.</p>
<p>Childhood is an important time to think about myopia because myopic children tend to become more nearsighted over time. The <a href="http://doi.org/10.1111/opo.12305">age of myopia onset</a> is the most significant predictor of severe myopia later in life.</p>
<p><iframe id="ZX4Fu" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/ZX4Fu/2/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Globally, <a href="http://doi.org/10.1186/s12886-019-1220-0">rates of myopia have been rising</a>. The prevalence of myopia among children ages 6-19 years is estimated at around 40% in Europe and North America, and higher in Asia. By midcentury, researchers studying the trends have estimated that <a href="https://linkinghub.elsevier.com/retrieve/pii/S0161642016000257">about half the world’s population could be myopic</a>.</p>
<p>Such high rates of myopia also come with an economic burden. The <a href="http://doi.org/10.1016/j.ophtha.2018.10.029">potential lost productivity</a> resulting from myopia was nearly US$250 billion in 2015.</p>
<h2>Building an eye-healthy lifestyle at home</h2>
<p>Parents can help by carefully managing their children’s screen time to support educational use while limiting cartoons and video games. They can also encourage more outdoors activities while maintaining social distancing.</p>
<p>Having <a href="https://doi.org/10.1177/0009922813498152">clear rules, setting limits on screen time</a> and <a href="http://doi.org/10.1186/s12889-015-2337-6">parents’ communication style</a> have been associated with less screen time among children. <a href="http://doi.org/10.1186/1479-5868-10-89">Parental modeling</a> also influences how much time children spend watching TV. </p>
<p>The <a href="https://www.who.int/publications-detail/guidelines-on-physical-activity-sedentary-behaviour-and-sleep-for-children-under-5-years-of-age">World Health Organization recommends</a> that children under 5 spend one hour or less per day on digital devices, and children under 1 spend no time on digital devices. The <a href="https://higherlogicdownload.s3.amazonaws.com/AAPOS/d8bb1f42-47c4-46d5-82af-1582d9d6e8f5/UploadedImages/Documents/CEF-10-Things.pdf">Children’s Eye Foundation recommends</a> daily outdoor play, no screen time for those under age 2, a maximum of 1-2 hours per day for kids ages 2 to 5 and guided screen time with frequent breaks for kids over 5.</p>
<p>Parents and teachers can also check out helpful tips for eye health <a href="https://www.aao.org/newsroom/news-releases/detail/is-too-much-screen-time-harming-childrens-vision">from the American Academy of Ophthalmology</a>. Educators can find <a href="https://www.aao.org/museum-research-resources">resources</a> to prepare learning materials. Here are some recommendations: </p>
<ul>
<li><p>Take a 20-second break from closeup work every 20 minutes</p></li>
<li><p>Set a timer to remind kids to take those breaks</p></li>
<li><p>Keep digital media 18 to 24 inches away from the face</p></li>
</ul>
<p>As we plan the future of education in the age of COVID-19, schools and policymakers must consider children’s vision needs while designing new initiatives. Schools, teachers and parents can work together to incorporate eye health strategies and protect children as they learn online.</p>
<p>[<em>The Conversation’s newsletter explains what’s going on with the coronavirus pandemic. <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=upper-coronavirus-daily">Subscribe now</a>.</em>]</p><img src="https://counter.theconversation.com/content/138193/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shu-Fang Shih, Research Assistant Professor of Health Policy and Management, received funding from the Ministry of Education in Taiwan from 2013 to 2018 . </span></em></p><p class="fine-print"><em><span>Olivia Killeen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>With online learning and social distancing, kids are spending more time staring at screens and less time outdoors. That can put them at higher risk of myopia and serious eye problems in the future.Shu-Fang Shih, Research Assistant Professor, Department of Health Management and Policy, School of Public Health, University of MichiganOlivia Killeen, Resident Physician in Ophthalmology, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1225302020-01-06T18:53:46Z2020-01-06T18:53:46ZShort-sightedness in kids was rising long before they took to the screens<figure><img src="https://images.theconversation.com/files/305814/original/file-20191209-90574-1adtn71.jpg?ixlib=rb-1.1.0&rect=482%2C1122%2C4621%2C2667&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Part of the cause of short-sightedness is also in our genes.</span> <span class="attribution"><span class="source">Shutterstock/Africa Studio</span></span></figcaption></figure><p>The number of people with <a href="https://www.healthdirect.gov.au/short-sightedness-myopia">myopia</a>, aka short-sightedness (difficulty seeing objects in the distance), has <a href="https://www.nature.com/news/the-myopia-boom-1.17120" title="The myopia boom">increased dramatically</a> in recent years in various regions of the world.</p>
<p>For example, in many cities in China <a href="https://www.scmp.com/magazines/post-magazine/long-reads/article/2085125/chinas-myopia-epidemic-why-simple-solution-being">more than 90% of university students</a> are living with myopia. In pure numbers this is one of the largest epidemics humanity has even seen, far greater than the obesity epidemic.</p>
<p>The myopia boom was first noted in 1980s in the cities of East Asian countries such as Korea, Taiwan and Singapore. The cities of China followed soon afterwards, and a similar trend is being <a href="https://www.sciencedirect.com/science/article/pii/S0161642015002808" title="Increasing Prevalence of Myopia in Europe and the Impact of Education">noted in Europe</a>.</p>
<h2>From blur to blindness</h2>
<p>For most people, myopia is merely an inconvenience requiring correction with glasses, contact lenses or refractive surgery.</p>
<p>Notably, myopia is associated with an increased <a href="https://www.ncbi.nlm.nih.gov/pubmed/29111299" title="Diagnosis and treatment guideline for myopic choroidal neovascularization due to pathologic myopia">risk of blindness</a> <a href="https://www.ncbi.nlm.nih.gov/pubmed/27898445" title="Pathologic Myopia">from retinal detachment, glaucoma and myopic macular degeneration</a>. Risk of blindness increased with worsening severity of myopia and this is a major public health concern.</p>
<p>Researchers and parents of children developing myopia have looked for explanations and the latest “suspect” is the <a href="https://theconversation.com/too-much-screen-time-linked-to-an-epidemic-of-myopia-among-young-people-111599">use of personal electronic devices</a>. </p>
<p>But the myopia epidemic in Asia preceded the release of smart phones by many years (the first iPhone was released in 2007).</p>
<p>New technologies – televisions in the 1960s, computers in the 1980s, laptops in the 1990s, and currently smartphones and tablets – have all been blamed for causing myopia.</p>
<p>As far back as the 1600s, the German astronomer <a href="https://www.britannica.com/biography/Johannes-Kepler">Johannes Kepler</a>, who first identified concave lenses could correct myopia, is said to have <a href="https://www.npr.org/templates/story/story.php?storyId=122374802">attributed his short-sightedness</a> to all his years of “intense study of astronomical tables and so forth”. But he might well have blamed <a href="https://www.history.com/topics/inventions/printing-press#section_5">Gutenberg</a>’s printed books (the latest technology at the time).</p>
<h2>What’s to blame for myopia?</h2>
<p>So what have researchers found so far?</p>
<p>Having parents with myopia <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4473431/" title="Association between parental myopia and the risk of myopia in a child">increases a child’s risk for myopia</a>. But children can mimic their parents’ potentially myopia-inducing lifestyle – such as near work that requires focusing on close-up objects and studying a lot inside – as well as inherit their genes.</p>
<p>After years of debate over whether myopia is due to genetic or environmental factors (with reading and screen use suggested), we now know it is an <a href="https://link.springer.com/article/10.1007/s10654-019-00512-7" title="Interaction between lifestyle and genetic susceptibility in myopia: the Generation R study">interaction of both genes and environment</a>.</p>
<p>Myopia does not result from a single gene defect; <a href="https://www.nature.com/articles/s41588-018-0127-7" title="Genome-wide association meta-analysis highlights light-induced signaling as a driver for refractive error">more than 160 interacting genes</a> contribute to the risk of myopia.</p>
<p>What are the environmental triggers that would explain an epidemic?</p>
<p>Many studies have looked at possible risk factors but only a few have come out consistently around the world: near work, <a href="https://www.bmj.com/content/361/bmj.k2248" title="Intense schooling linked to myopia">years in education</a> and lack of <a href="https://www.sciencedirect.com/science/article/pii/S0161642012003636" title="The Association between Time Spent Outdoors and Myopia in Children and Adolescents: A Systematic Review and Meta-analysis">time spent outdoors in daylight</a>. </p>
<p>Untangling the interactions is a challenge because these factors are interrelated, with children who study more spending less time outdoors. </p>
<h2>Don’t just blame the technology</h2>
<p>Despite decades of parents warning children, no study has shown that sitting too close to the television causes myopia.</p>
<p>In the past two years, five papers (<a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215827" title="Impact of various types of near work and time spent outdoors at different times of day on visual acuity and refractive error among Chinese school-going children">1</a>, <a href="https://www.tandfonline.com/doi/full/10.1080/00140139.2018.1562107" title="Mobile touch screen device use and associations with musculoskeletal symptoms and visual health in a nationally representative sample of Singaporean adolescents">2</a>, <a href="https://bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-017-0519-y" title="Association of lifestyle and body structure to ocular axial length in Japanese elementary school children">3</a>, <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/aos.14242" title="Low physical activity and higher use of screen devices are associated with myopia at the age of 16‐17 years in the CCC2000 Eye Study">4</a> and <a href="https://bjo.bmj.com/content/103/8/1078.long" title="Early life factors for myopia in the British Twins Early Development Study">5</a>) have looked at myopia and personal electronic devices. Some, but not all, have found an association between the amount of screen use and myopia. But this does not mean screen time itself causes myopia. </p>
<p>Instead of reading from books, children are reading more from screens and changing the nature of their near work. Rising rates of myopia are related to near work behaviours, rather than screen use in particular.</p>
<p>Children are also changing the way they use screens. The simple idea that screen use occurs indoors was completely overthrown by the <a href="https://theconversation.com/au/topics/pokemon-go-29173">Pokémon Go</a> craze, as <a href="https://theconversation.com/the-pokemon-go-craze-sees-gamers-hit-the-streets-but-it-comes-with-a-warning-62278">gamers headed outdoors with their smartphones</a> in search of virtual treats. </p>
<p>In addition, we now have children using virtual reality goggles to play games or even study.</p>
<h2>Limits on screen time</h2>
<p><a href="https://www1.health.gov.au/internet/main/publishing.nsf/content/health-pubhlth-strateg-phys-act-guidelines">Australian guidelines</a> recommend: </p>
<ul>
<li>children under two years of age have no screen time</li>
<li>two to five-year-old children have a maximum of one hour a day</li>
<li>five to 17-year-old children be limited to two hours of recreational screen time per day.</li>
</ul>
<p>There is no rigorous scientific basis for these time limits in relation to visual health. But a recent <a href="https://www.mja.com.au/journal/2019/211/4/adherence-screen-time-recommendations-australian-children-aged-0-12-years">study</a> showed a large percentage of children exceeded these time limits.</p>
<p>Potential health issues relating to screen time are diverse. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6388165/" title="Impact of Adolescents’ Screen Time and Nocturnal Mobile Phone-Related Awakenings on Sleep and General Health Symptoms: A Prospective Cohort Study">Sleep</a>, <a href="https://www.tandfonline.com/doi/full/10.1080/00140139.2018.1562107" title="Mobile touch screen device use and associations with musculoskeletal symptoms and visual health in a nationally representative sample of Singaporean adolescents">posture</a>, <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.01999590" title="Association between mobile technology use and child adjustment in early elementary school age">level of physical activity and behavioural issues</a> are additional reasons for concern.</p>
<h2>Just go outside more</h2>
<p>Unlike previous generations, most children today experience a lot of screen time. But we don’t have consistent findings for use of television, computers, tablets, smart phones or even virtual reality goggles themselves as the main cause of myopia.</p>
<p>We clearly need some very large, well-conducted studies, where we directly measure the use of screen time across a wide range of health issues from infancy to young adulthood. </p>
<p>Some cities in China are <a href="https://jamanetwork.com/journals/jama/fullarticle/2441261" title="Effect of Time Spent Outdoors at School on the Development of Myopia Among Children in China">trialling</a> scheduled time spent outdoors at school to see if it prevents or decreases the progression of myopia in children. </p>
<p>In Australia, we need tailored messages to encourage kids to spend more time outdoors if they are inside reading or using screens too much.</p><img src="https://counter.theconversation.com/content/122530/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Mackey receives funding from NHMRC. </span></em></p>Too much studying and staying indoors are more likely to blame for the rise in the number of children with myopia, or short-sightedness.David Mackey, Professor of Ophthalmology, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1224272019-09-26T21:29:29Z2019-09-26T21:29:29ZPoor vision: Do drivers always see what is happening on the road?<figure><img src="https://images.theconversation.com/files/293675/original/file-20190923-54813-9e0ufe.jpg?ixlib=rb-1.1.0&rect=102%2C87%2C4469%2C2646&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Vision is the most important source of information on which driving conduct is based. Poor vision of drivers has been found to be the cause of many accidents.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/">Shutterstock</a></span></figcaption></figure><p>A <a href="https://www.cbc.ca/news/canada/montreal/highway-330-bonnardel-1.5247853">recent tragic pile-up on a major highway near Montreal</a> has spurred the Québec government into action — to find the best ways to improve roads and prevent such disasters from happening again.</p>
<p>However, this investigation into the crashes on Highway 440 which left four people dead did not mention the main tool for safe driving — vision.</p>
<p>The <a href="https://www.ncbi.nlm.nih.gov/pubmed/24563119">Cochrane Institute published an analysis in 2014</a> indicating that vision is the most important source of information on which to assess driving. Poor vision of drivers is one of the causes of many accidents.</p>
<p>The potential causes of vision impairment are well known: cataracts, macular degeneration, diabetic retinopathy, glaucoma and corneal scars, to name a few. In addition, there are binocular vision problems (visual coordination) that can lead to unstable, double vision, lack of third dimensional perception and<a href="https://www.ncbi.nlm.nih.gov/pubmed/21870915"> delayed reaction to an unexpected event</a>, such as a child appearing in front of the car.</p>
<p>Finally, refractive errors are also very present. <a href="https://www.mayoclinic.org/diseases-conditions/farsightedness/symptoms-causes/syc-20372495">Uncorrected hyperopia (farsightedness) can lead to drowsiness while driving</a>. A myopic and/or astigmatic person who does not wear his glasses while driving — it often happens, believe it or not — does not see well into the distance, at least not to a safe distance allowing him to anticipate incidents.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288539/original/file-20190819-123720-xsve0g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288539/original/file-20190819-123720-xsve0g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288539/original/file-20190819-123720-xsve0g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288539/original/file-20190819-123720-xsve0g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288539/original/file-20190819-123720-xsve0g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288539/original/file-20190819-123720-xsve0g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288539/original/file-20190819-123720-xsve0g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Binocular vision problems can lead to unstable, double vision, lack of perception of the third dimension, as well as a delayed reaction to an unexpected event, such as a child who appears in front of the car.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Young people also affected</h2>
<p>Although the incidence of visual pathologies and problems increases with age, some of them also impact younger drivers. More than 200,000 Québecers are affected by a combination of <a href="http://www.vision2020canada.ca/en/resources/Pages/default.aspx">all types of eye problems</a>. That suggests that each time you venture onto the road, you are likely to encounter a driver who is affected by an eye or visual impairment that puts his or her driving at risk.</p>
<p>In addition to visual acuity, other elements of visual function contribute to safe driving. For example, <a href="https://www.ncbi.nlm.nih.gov/pubmed/12517356">the visual function includes an intrinsic element of perception</a>. That allows you to grasp a scene that takes place in front of your eyes with the best possible clarity, your eye movements allowing you to appreciate the dynamics of the scene. The study of visual function — and not just visual acuity — is therefore essential to reducing the number of accidents.</p>
<p>Mosty eye problems or <a href="https://www.ncbi.nlm.nih.gov/pubmed/25000871">abnormalities of oculo-visual function are asymptomatic</a> and are only detected during a complete examination by an optometrist. This is particularly the case with diabetic retinopathy or ocular lesions, already present in <a href="http://guidelines.diabetes.ca/Browse/Chapter30">25 per cent of patients at the time of diagnosis</a>.</p>
<h2>Lax regulations</h2>
<p>While science confirms the importance of vision to safe driving, regulatory agencies treat this element negligently. They only require often inappropriate or late checks on the visual condition of drivers. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288536/original/file-20190819-123749-48rhyv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288536/original/file-20190819-123749-48rhyv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288536/original/file-20190819-123749-48rhyv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288536/original/file-20190819-123749-48rhyv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288536/original/file-20190819-123749-48rhyv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288536/original/file-20190819-123749-48rhyv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288536/original/file-20190819-123749-48rhyv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Although science confirms the importance of vision for safe driving, regulatory agencies are often lax about this element.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>For example, the screening test conducted in the service centres of the <a href="https://saaq.gouv.qc.ca/en/">Société de l'assurance automobile du Québec</a> (the Québec auto insurance board) when a temporary permit is issued is very brief and neglects fundamental aspects of eye health. The SAAQ requires more comprehensive tests much later for the majority of drivers.</p>
<p>In the case of private vehicles (classes 5 and 6), the examination is required at age 75 and then from age 80, every two years. For commercial vehicles (classes 1 to 4), if driving involves a presence in the United States, an examination is required every five years until age 45, then every three years from age 45 to 65. However, if the driver lives in the rest of Canada, his or her examination is generally only required at age 45, then every five years from age 55 to 65 and every two years thereafter. </p>
<p>The provinces, which follow National Safety Code standards and the <a href="https://ccmta.ca/images/pdf-documents-english/CCMTA-Medical-Standards-2017-English.pdf">Canadian Council of Motor Transport Administrators Medical Standards for Drivers</a>, also add other conditions in certain circumstances as well. For example, Ontario and Alberta require vision testing when a driver requests a change in the classification of their licence. Ontario also requires vision testing when a licence has been expired for more than a year or when an optometrist advises of any issues with a driver’s vision. </p>
<p>There is no reason for such varying standards. The risk is the same everywhere. Although periodic inspection of drivers from the age of 45 is happening, it would seem more important to carry out a full assessment of everyone when they apply for a licence.</p>
<h2>Recommendations left unheeded</h2>
<p>Lack of adequate regulation prompted the Ordre des Optométristes du Québec (Quebec Order of Optometrists) to create <a href="https://auto.lapresse.ca/actualites/201703/03/01-5075284-securite-routiere-examen-de-la-vue-obligatoire-des-65-ans-plutot-qua-75-.php">specific recommendations during the provincial transportation ministry’s consultation in 2017</a>. </p>
<p>The Order proposed that the statutory examination for Class 5 and 6 drivers be scheduled for at least 70 years of age, and possibly even 65 years. It also suggested that statutory examination for commercial drivers (Class 1 to 4) be applied in the same way, whether or not the driver drives in the United States. The examination of these drivers should include a complete eye and visual examination.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288538/original/file-20190819-123727-wu3ykn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288538/original/file-20190819-123727-wu3ykn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288538/original/file-20190819-123727-wu3ykn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288538/original/file-20190819-123727-wu3ykn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288538/original/file-20190819-123727-wu3ykn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288538/original/file-20190819-123727-wu3ykn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288538/original/file-20190819-123727-wu3ykn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Order of Optometrists recommends that the statutory audit examination be moved to age 65, instead of age 75 as is currently the case.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>The Order also proposed that assessment tests conducted at the time of obtaining a driver’s licence should not be limited but should cover the detection of abnormalities in refraction, <a href="https://www.ncbi.nlm.nih.gov/pubmed/20385890">visual field</a>, binocular vision and screening for eye diseases that may influence driving. </p>
<p>These recommendations, which have not yet been adopted by the authorities, are scientifically justified. They are also full of common sense, insofar as we must be concerned about the safety of road users and in order to improve the driving record in Quebec.</p>
<h2>It’s time to act</h2>
<p>By recognizing vision as a key element of safe driving, policy makers and public agencies would make a significant contribution to improving road conditions across the country. </p>
<p>Drivers themselves must be proactive by consulting their eye-care professional on a regular basis. They must comply with their recommendations. They must also adequately treat any ocular or visual condition that could lead to sight loss or dysfunction of visual perception.</p>
<p>[ <em>Deep knowledge, daily.</em> <a href="https://theconversation.com/ca/newsletters?utm_source=TCCA&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/122427/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Langis Michaud ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>When you head out onto the road, there’s always a chance that you might encounter a driver who has a vision problem, putting his or her driving at risk. Regulations need to change.Langis Michaud, Professeur Titulaire. École d'optométrie. Expertise en santé oculaire et usage des lentilles cornéennes spécialisées, Université de MontréalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1180312019-06-11T23:09:05Z2019-06-11T23:09:05ZFrom obesity to allergies, outdoor play is the best medicine for children<figure><img src="https://images.theconversation.com/files/278978/original/file-20190611-32356-13o88s8.jpg?ixlib=rb-1.1.0&rect=0%2C59%2C4984%2C3183&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Children report being at their happiest when playing outside.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>What if there was a simple, inexpensive and fun way to address some of the major challenges facing humanity today. What if it could help improve children’s health, development and well-being?</p>
<p>Imagine a solution that could stem the <a href="https://doi.org/10.1016/S0140-6736(17)32129-3">current epidemics of obesity</a>, anxiety and <a href="https://doi.org/10.1016/j.cpr.2009.10.005">depression</a> affecting children and youth today. Imagine that this solution could also promote brain health, creativity and academic achievement and prepare our children for the <a href="https://www.realplaycoalition.com/value-of-play-report/">rapidly-changing work force</a>. </p>
<p>Along the way it could reduce incidence of allergies, asthma and other <a href="https://doi.org/10.1073/pnas.1205624109">immunity challenges</a> and <a href="https://doi.org/10.1111/cxo.12845">improve eye health</a>. It could <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/indigenizing-outdoor-play">foster a culture of environmental stewardship and sustainability</a> and help build the health of cities — promoting neighbourliness and <a href="https://doi.org/10.1016/j.socscimed.2010.12.015">feelings of community connection</a>. </p>
<p>Imagine that this intervention could also help countries meet their targets for many of the <a href="https://www.un.org/sustainabledevelopment/sustainable-development-goals/">United Nations Sustainable Development Goals</a>, such as the goals of Good Health and Well-being, Inclusive and Equitable Quality Education, Decent Work and Economic Growth and Climate Action.</p>
<p>This isn’t an expensive intervention, or one that parents have to force their children to do — like homework or eating their vegetables. Rather than dreading it, <a href="https://doi.org/10.1080/21594937.2014.937963">children report being at their happiest</a> when doing it and they seek ways to keep at it for as long as possible.</p>
<p>What is this fix-all simple solution? Playing outside.</p>
<h2>The magic of outdoor play</h2>
<p>Many of us have <a href="https://www.jstor.org/stable/10.7721/chilyoutenvi.26.1.0017">fond memories of childhoods spent outside</a>, hanging out with friends in our neighbourhoods, parks and wild places, making up the rules as we went along, with minimal (if any) adult supervision. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/278984/original/file-20190611-32356-1vvvbdz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/278984/original/file-20190611-32356-1vvvbdz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/278984/original/file-20190611-32356-1vvvbdz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/278984/original/file-20190611-32356-1vvvbdz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/278984/original/file-20190611-32356-1vvvbdz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/278984/original/file-20190611-32356-1vvvbdz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/278984/original/file-20190611-32356-1vvvbdz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Children need the time, space and freedom to play outdoors.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>We need only reflect on our own play memories to realize how valuable these experiences can be and how they can shape our lifelong health and development. The research is now catching up to our intuitions, recognizing the <a href="http://www.child-encyclopedia.com/outdoor-play/">vast and diverse benefits of outdoor play</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-kids-need-risk-fear-and-excitement-in-play-81450">Why kids need risk, fear and excitement in play</a>
</strong>
</em>
</p>
<hr>
<p>Playing outside is not the same as playing inside. There are <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/topic-commentary-why-outdoor-play">unique benefits of being in the outdoors</a>, particularly in nature, that don’t come as readily indoors. When children are allowed to play the way they want to play in stimulating environments, <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/active-outdoor-play">they move more, sit less and play longer</a>. </p>
<p>They get their hands in the dirt and are <a href="http://letthemeatdirt.com/">exposed to microbes that help them build their immunity</a>. They make their own goals and figure out the steps to attain those goals, helping them build <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/influence-outdoor-play-social-and-cognitive-development">executive function skills</a>. They <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/young-childrens-outdoor-play-based-learning">learn</a>, build resilience and <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/influence-outdoor-play-social-and-cognitive-development">develop their social skills</a>, learn how to <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/outdoor-risky-play">manage risks</a> and keep themselves safe. Their eyes get the exercise they need to help combat <a href="https://doi.org/10.1111/cxo.12845">short-sightedness</a>.</p>
<p>We are rediscovering the magic of outdoor play. Governments see it as a way of <a href="http://www.phn-rsp.ca/aop-position-jae/index-eng.php">getting kids active</a> and averting the obesity crisis. Schools and <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/building-capacity-support-outdoor-play-early-childhood-education">early childhood centres</a> see it as a way of promoting academic and socio-emotional learning. Corporations see it as a way of <a href="https://www.weforum.org/agenda/2019/01/play-gap-hurting-childrens-skills-futures">preparing children for the jobs of the future</a> that will focus on creativity, empathy and connection with others. Children just see it as a way of having fun and feeling free!</p>
<h2>Adults must let go of their fears</h2>
<p>There are three key ingredients to supporting outdoor play: <a href="http://www.playwales.org.uk/eng/outdoorplay">time, space and freedom</a>.</p>
<p>Kids need time to be able to play outside. In schools, that means <a href="https://files.eric.ed.gov/fulltext/EJ1137793.pdf">recess policies that get kids outside every day</a>, finding opportunities to use the outdoors for learning and limiting homework. At home, that means laying aside screens and limiting scheduled structured activities.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/278988/original/file-20190611-32331-12mgj2z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/278988/original/file-20190611-32331-12mgj2z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/278988/original/file-20190611-32331-12mgj2z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/278988/original/file-20190611-32331-12mgj2z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/278988/original/file-20190611-32331-12mgj2z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/278988/original/file-20190611-32331-12mgj2z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/278988/original/file-20190611-32331-12mgj2z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Risky play teaches children to keep themselves safe.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Kids also need <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/early-childhood-outdoor-play-and-learning-spaces-ecopals-achieving">high quality outdoor spaces</a> to play in. That doesn’t necessarily mean expensive playground equipment. It means <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/creating-inclusive-naturalized-outdoor-play-environments">spaces where all children feel welcome</a>, regardless of their abilities and backgrounds, that they can make their own and that also have loose parts (for example sticks, stones, water and cardboard boxes) they can use and let their imagination shape the play. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/five-tips-to-manage-screen-time-this-summer-97844">Five tips to manage screen time this summer</a>
</strong>
</em>
</p>
<hr>
<p>In cities, that means being prepared for and allowing play to happen everywhere, not just parks and playgrounds. We need to design <a href="http://www.child-encyclopedia.com/outdoor-play/according-experts/designing-cities-outdoor-play">inclusive and child-friendly cities</a> where kids feel welcome everywhere and can easily access nature.</p>
<p>Finally, freedom: the biggest barrier to children’s ability to play the way they want to play is adults. We need to <a href="https://theconversation.com/why-kids-need-risk-fear-and-excitement-in-play-81450">let go of our excessive fears of injuries and kidnapping</a> and realize that the benefits of kids getting out to play far outweigh the risks. My lab developed a <a href="https://outsideplay.ca/">risk reframing tool for parents and caregivers to help them on this journey</a>.</p>
<h2>Support the children in your life</h2>
<p>Helping support children’s outdoor play can be as simple as opening the front door. It doesn’t have to be complicated or expensive. If we all do our bit, we can help bring back this crucial activity that should be part of all children’s daily lives, regardless of age, cultural background, gender or ability. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/278989/original/file-20190611-32317-1hy7cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/278989/original/file-20190611-32317-1hy7cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=378&fit=crop&dpr=1 600w, https://images.theconversation.com/files/278989/original/file-20190611-32317-1hy7cs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=378&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/278989/original/file-20190611-32317-1hy7cs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=378&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/278989/original/file-20190611-32317-1hy7cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=475&fit=crop&dpr=1 754w, https://images.theconversation.com/files/278989/original/file-20190611-32317-1hy7cs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=475&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/278989/original/file-20190611-32317-1hy7cs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=475&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Playing outdoors reduces incidence of allergies, asthma and other immunity challenges.</span>
<span class="attribution"><span class="source">(Unsplash/Matthew T Rader)</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>There are lots of <a href="https://www.cpha.ca/unstructured-play">tools to help you get started</a>, whether you’re a parent, caregiver, <a href="http://lawson.ca/advancing-op-ece.pdf">educator</a>, city planner or a neighbour. </p>
<p>I would encourage you to consider one simple and attainable thing you are going to do today to help get the child or children in your life get out to play.</p><img src="https://counter.theconversation.com/content/118031/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mariana Brussoni receives funding from the Canadian Institutes of Health Research, the Lawson Foundation and salary support from the BC Children's Hospital Research Institute. She is a board member of the Child & Nature Alliance of Canada.</span></em></p>Adults must let go of their fears of injury and kidnapping. Children need free outdoor play to build physical immunity, psychological health, executive functioning and social skills.Mariana Brussoni, Associate Professor of Pediatrics and Population and Public Health, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1115992019-02-12T22:48:25Z2019-02-12T22:48:25ZToo much screen time linked to an epidemic of myopia among young people<figure><img src="https://images.theconversation.com/files/258623/original/file-20190213-90497-18zyb99.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Today’s young people don’t play outside as much as their predecessors and are heavy users of electronics.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Ask anyone about the benefits of technology and it probably won’t take them long to rhyme off a list of examples: it helps broaden your knowledge, connect with friends, both new and old, and allows you to see things you’ve never seen before.</p>
<p>But what about the drawbacks? Here’s a major one: increased screen time is hard on your eyes.</p>
<p>In fact, more and more young people are wearing glasses to correct their nearsightedness. This trend has prompted optical health experts to determine if the use of electronic devices such as computers, tablets and smart phones is leading to a deterioration in sight that is reaching epidemic proportions.</p>
<p>Let’s take the example of Pauline — although she could just as easily be a David or a Jason. She is 10 years old and a studious child, doing well in school. Like any young person her age, she loves to use her tablet computer to study or have fun. She’s on it two hours a day, plus weekends.</p>
<p>Pauline may be in for a change, however. She has recently been diagnosed with nearsightedness and her optometrist has strongly recommended that she — and her parents — limit her use of electronic devices and spend more time playing outside.</p>
<p>Pauline isn’t happy. She thinks it’s not fair.</p>
<p>But her case raises the question: what is the link between the use of electronic devices and the appearance of myopia?</p>
<h2>A public health issue</h2>
<p>Forty per cent of North Americans are affected by myopia. The number of cases <a href="https://www.ncbi.nlm.nih.gov/pubmed/18695106">doubled between 1972 and 2004</a> and continues to grow at a rate that <a href="https://www.ncbi.nlm.nih.gov/pubmed/24357836">qualifies the phenomenon as an epidemic</a>.</p>
<p>In Europe, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4504030/#sec2title">myopia is prevalent among 42.2 per cent of adults aged 25 to 29 years</a>, almost twice that of adults aged 55 to 59 years.</p>
<p>This suggests there is a real public health issue facing us — and not just the common problem of an error in the refraction of the eye which shows up as blurred vision when looking into the distance.</p>
<p>In fact, high amounts of myopia <a href="https://www.ncbi.nlm.nih.gov/pubmed/22772022">significantly increases the risk of major ocular health disorders </a>such as retinal tearing (21 times greater), glaucoma (40 times) or cataracts (six times).</p>
<p>An eye that becomes short-sighted becomes longer. The stretching is proportional to <a href="https://www.ophthalmologymanagement.com/issues/2012/july-2012/measuring-axial-length">the increase in myopia</a>. The more the eye stretches, the more the retina, which lines the inside of the eye, becomes thinner. Symptoms such as cracks, abnormal development of subretinal blood vessels and bleeding may appear.</p>
<p>Ultimately, the very nearsighted patient has a more than 50 per cent risk of spending the rest of his or her life legally blind — in other words living with vision reduced by 60 per cent. This means that the <a href="https://www.ncbi.nlm.nih.gov/pubmed/20363029">length of their eye exceeds 28 mm</a> (the normal length is 23 mm) or that <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=Tideman+JAMA+ophthalmol">the myopia levels exceeds six diopters</a>. (Diopters is a unit of measurement used to calculate eyesight — the further away from zero indicates a worsening in vision.) It is important to intervene before this happens to avoid these levels.</p>
<p>(In Canada, <a href="https://www.epso.ca/vision-health/general-interest/legal-blindness/">legal blindness is defined by a visual acuity of less than 20/200 </a>in the best eye with the help of glasses or contact lenses. A legally blind person therefore sees, at best, 20 times worse than a person with normal acuity.)</p>
<h2>What’s behind the epidemic?</h2>
<p>There are many causes of onset myopia. Genetics plays an important role but epigenetics — the environment in which the child evolves — is <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=Rong+Asia+Pacific+Pacific+J+Ophthalmol">a more important factor</a>.</p>
<p>And what has changed in our environment to explain the recent myopia epidemic? The impact of technology, which has seen a boom in recent years, is being closely examined.</p>
<p>For example, a rapid increase in visual problems has been noted since the introduction of the smartphone in 2007. While the device itself does not emit harmful radiation, it requires the user to read its screen at a distance of 20 cm rather than the normal distance of 45 cm to 50 cm. It has been suggested that this close distance <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4473431/">boosts the risk of developing myopia by eight times</a>, especially if both parents are myopic.</p>
<p>Ambient lighting also plays a role because <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4526691/">the use of fluorescents</a>, such as in classrooms, also promotes myopia. When a tablet is used in such an environment, the effect is multiplied tenfold.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/252534/original/file-20190104-32142-2rkjfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/252534/original/file-20190104-32142-2rkjfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=303&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252534/original/file-20190104-32142-2rkjfs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=303&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252534/original/file-20190104-32142-2rkjfs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=303&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252534/original/file-20190104-32142-2rkjfs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=380&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252534/original/file-20190104-32142-2rkjfs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=380&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252534/original/file-20190104-32142-2rkjfs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=380&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Unlike paper books, tablet and computer screens emit blue light. The short wavelengths from blue light are perceived in front of the others by the eye, which generates a myopia stimulus.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Unlike books printed on paper, tablet and computer screens are optically associated with so-called chromatic aberrations. The shortest wavelengths (blue light) are perceived in front of the others by the eye, which generates a myopia stimulus. There is a dose and response effect here, suggesting that prolonged use leads to more negative effects.</p>
<p>Today’s young people don’t play outside as much as their predecessors and are heavy users of electronics. However, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474591/">exposure to daylight has a protective effect against myopia</a>. These beneficial effects are decreased, but not negligible, <a href="https://www.ncbi.nlm.nih.gov/pubmed/30288926">during less sunny months</a> or when <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5599950/">myopia is already present</a>.</p>
<h2>Possible solutions</h2>
<p>The purpose of myopia treatment is to reduce the rate of progression of the dioptric, but above all to slow down the elongation of the eye. If, obviously, we cannot play with genetics, it is imperative to influence epigenetics and therefore the environment in which the child evolves.</p>
<p>Therefore, using any electronic media before the age of two should be avoided, <a href="http://pediatrics.aappublications.org/content/pediatrics/early/2011/10/12/peds.2011-1753.full.pdf">even if it’s only for a few minutes</a>. A limit of one hour per day should be the rule for those between two and five years of age and the emphasis should be put on educational sites or applications that promote interactions between the parent and child.</p>
<p>While school requests should be taken into consideration, the use of electronic media should continue to be limited as the child gets older. A maximum of one hour, besides school work, must be observed for good eye health. A two-minute break after every 30 minutes of device use will also lessen harmful effects and <a href="https://bmjopen.bmj.com/content/5/1/e006748">exposure to a device should be avoided at least one hour before sleep.</a></p>
<p>Children should also get a minimum of 45 minutes of daylight per day. They can get this by walking to school or participating in such activities as regular outdoor sports.</p>
<p>The next step is to ensure the co-ordination of both eyes, from far away but especially close up. An optometrist will need to perform an orthopic check-up and correct, by exercise or optical means, any anomaly that may have been detected.</p>
<p>Finally, optical correction must be chosen with the goal of slowing down the progression. In rare cases, glasses with anti-myopia lenses may be prescribed. They provide a <a href="https://www.ncbi.nlm.nih.gov/pubmed/26826749">deceleration rate of about 30 per cent </a>. Specialized contact lenses are often preferred and offer control ranging from 50 per cent to 80 per cent. The contact lens treatment is available from the age of seven, and will be periodically reassessed according to the child’s changing needs.</p>
<p>In short, myopia is not just a commonplace vision defect. It is a significant risk factor for serious eye disease. We must therefore do everything possible to slow its progress and protect our children’s vision — and that means also reviewing their relationship with electronic devices.</p><img src="https://counter.theconversation.com/content/111599/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Langis Michaud has received funding from: Johnson and Johnson, Bausch and Lomb, Cooper Vision and is a member of l'Association des Optométristes du Québec.</span></em></p>Myopia is a major risk factor for serious eye diseases. It has become epidemic among children, particularly because of their heavy use of electronic devices.Langis Michaud, Professeur Titulaire. École d'optométrie. Expertise en santé oculaire et usage des lentilles cornéennes spécialisées, Université de MontréalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1063742018-11-12T09:01:45Z2018-11-12T09:01:45ZModern life offers children almost everything they need, except daylight<figure><img src="https://images.theconversation.com/files/244104/original/file-20181106-74751-1be3qbk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/148995752?src=WdMz3b9-sSBQujY8FOHEnQ-1-0&size=medium_jpg">Sergey Novikov/Shutterstock</a></span></figcaption></figure><p>The debate about the volume of homework that children are being given has been bouncing around the opinion pages of <a href="https://www.thetimes.co.uk/article/why-the-hippies-are-wrong-about-homework-c76bz57qd">broadsheets</a> and <a href="https://www.thesun.co.uk/tvandshowbiz/7348546/piers-morgan-gary-lineker-homework-row/">red tops</a> in recent weeks after Gary Lineker tweeted that it was “<a href="https://twitter.com/garylineker/status/1044528524705640448?lang=en">a waste of time</a>”. As names are called and sides are taken in the debate there are much bigger issues at stake than either side is admitting. </p>
<p>As children are given ever more homework we must concede that cramming a child’s day with indoor activities is rolling the dice with their long-term health. As adults, we now spend more time indoors than we have ever done throughout the history of our species. While our indoor habits have implications for our own health, there is more at stake when we encourage this behaviour in our children. </p>
<p>Already, most children are schooled indoors. At the end of their day, there is perhaps an after-school club, tuition or homework to do. When all those are complete, gaming, streaming and social media beckon. As a result, nearly three-quarters of children in the UK spend <a href="https://www.theguardian.com/environment/2016/mar/25/three-quarters-of-uk-children-spend-less-time-outdoors-than-prison-inmates-survey">less time outdoors than prison inmates</a>.
A <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/498944/mene-childrens-report-years-1-2.pdf">2016 report</a> concluded that 12% of children in the UK had not been to a park or natural environment at all in the preceding year. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1044528524705640448"}"></div></p>
<h2>Short-sighted</h2>
<p>Outdoor time is essential for children because it helps their eyes, bones and immune systems develop correctly. Evidence is also mounting that it may prevent the onset of food, nut and other allergies. </p>
<p>Babies are born longsighted, with a short eyeball that grows as their bodies do. A healthy eye stops growing when it reaches its optimum shape, but it struggles to do this without access to good quality light – which is only available outdoors. Our eyes are very good at tricking us into believing that our indoor environments are well lit – but even a brightly lit room cannot match the levels of outdoor light, even a cloudy day outside.</p>
<p>Without the correct daylight cues, the eyeball can grow too long, making the child shortsighted; at which point, they will need lenses or surgery to correct their vision. And it’s not just a matter of wearing glasses or paying for some laser surgery. Severe myopia – about a fifth of cases – can lead to blindness in older age. Even though laser surgery can restore vision, the damage done to the eye during development remains, as do the risks. </p>
<p>Several countries in South-East Asia are well ahead of the UK in driving these indoor lifestyles. Most people in Singapore (85%) are shortsighted. Throughout the region, rates are highest among the young. A staggering <a href="https://iovs.arvojournals.org/article.aspx?articleid=2166142">96.5% of 19-year-old men</a> in South Korea’s capital, Seoul, are myopic. And while there are a couple of hundred genes at play in the outcome of myopia, the numbers we are seeing are being driven by lifestyle (because it’s believed that genes play only a small to moderate role in the disease’s architecture). </p>
<p>Shortsightedness among the young in the UK has more than doubled <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0146332">in the last 50 years</a>. It is predicted that if nothing is done to curb its spread, half the world’s population will be <a href="https://bit.ly/2OqJWoc">myopic by 2050</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/244285/original/file-20181107-74787-j31wd2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/244285/original/file-20181107-74787-j31wd2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/244285/original/file-20181107-74787-j31wd2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/244285/original/file-20181107-74787-j31wd2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/244285/original/file-20181107-74787-j31wd2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/244285/original/file-20181107-74787-j31wd2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/244285/original/file-20181107-74787-j31wd2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Severe myopia can lead to blindness in old age.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/749235478?src=1mMOlwcEx3w6hjgEJ3gdeg-1-0&size=medium_jpg">Lapina/Shutterstock</a></span>
</figcaption>
</figure>
<h2>The sunshine vitamin</h2>
<p>Shady living is also in the frame for the return of a disease that was thought to have been eradicated after World War II. Sunlight is essential for our body to make vitamin D. Without it, we cannot absorb calcium and phosphate, which we need for healthy bones, teeth and muscles. Endless indoor hours are contributing to the <a href="https://www.theguardian.com/society/2017/dec/23/poorer-children-disproportionately-need-hospital-treatment">return</a> of <a href="https://www.nhs.uk/conditions/rickets-and-osteomalacia/">rickets</a> among children in the UK. Rickets causes pain, poor growth and soft or weak bones that bend under the weight of the torso.</p>
<p>Vitamin D deficiency has also been associated with the rise of <a href="https://www.mcri.edu.au/news/investigating-allergies-food-allergy-capital">food and nut allergies</a>, where scientists have noticed that the prevalence increases the further you get from the equator. A lack of outdoor time and lack of exposure to natural environments have also been linked to the huge upturn in allergies more broadly, such as <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/cea.12527">hay fever</a> and <a href="https://www.nejm.org/doi/full/10.1056/NEJMoa1508749?viewType=Print&viewClass=Print&sort=newest&page=-15">asthma</a>, as well as type 1 diabetes. In the case of the latter, it has been suggested that “<a href="https://www.ncbi.nlm.nih.gov/pubmed/26729037">rapid environmental changes and modern lifestyles</a>” are probably behind the increase.</p>
<p>All of these diseases are telling us that, while urban life offers us many comforts and advantages, it is a lifestyle that is confusing to the modern human body. I know from having <a href="https://www.octopusbooks.co.uk/books/detail.page?isbn=9781788401081">researched a book on the way our environment is changing us</a> that we carry DNA which expects us to be performing a wide array of outdoor activities, and not to be spending all our time reading, streaming or playing <a href="https://www.epicgames.com/fortnite/en-US/buy-now/battle-royale">Fortnite</a>. </p>
<p>Making small changes, such as giving your children more access to daylight, even when it’s cloudy, and encouraging regular physical activity, will set them up for a much healthier future. Getting your children to go out and play is not some hippy notion, it is an essential component of their long term health.</p><img src="https://counter.theconversation.com/content/106374/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vybarr Cregan-Reid does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A strong case for telling children to go outside and play.Vybarr Cregan-Reid, Reader in Environmental Humanities, University of KentLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/836932017-09-26T00:17:07Z2017-09-26T00:17:07ZWhy your kids might be able to see better if they play outdoors more often<figure><img src="https://images.theconversation.com/files/186424/original/file-20170918-8241-mlsht1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There are many health benefits to kids playing outdoors, not the least of which is preventing myopia. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/kids-playing-together-during-sunny-day-573161818?src=wW3lGEBJ4QQwZQY8yav7Lw-1-9">wavebreakmedia/www.shutterstock.com</a></span></figcaption></figure><p>The ready availability of technology may make the children of today faster at configuring a new smartphone, but does all of that screen time affect the development of their eyes?</p>
<p>While conventional wisdom dictates that children should do less up-close viewing, sit farther from the television and perhaps even wear their eyeglasses less, we have found in recent studies that another factor may be at play: Kids need to go outside, and, if not play, at least get some general exposure to outdoor light.</p>
<p>To our surprise, more time outdoors had a protective effect and reduced the chances that a child would go on to need myopic refractive correction in the future. The <a href="http://iovs.arvojournals.org/article.aspx?articleid=2183997">size of the effect</a> was impressive.</p>
<h2>What causes nearsightedness?</h2>
<p><a href="https://nei.nih.gov/health/errors/myopia">Myopia</a>, or nearsightedness, is a condition in which you can’t see far away but can see up close – without glasses or contact lenses. It typically starts during the early elementary school years. Because kids don’t know how other kids see, they often think their blurry vision is normal, so regular eye examinations are important during childhood.</p>
<p>With myopia, the eye is growing, but growing too long for distant rays of light to focus accurately on the back of the eye. A blurry image results.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/186431/original/file-20170918-13207-naako8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/186431/original/file-20170918-13207-naako8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=462&fit=crop&dpr=1 600w, https://images.theconversation.com/files/186431/original/file-20170918-13207-naako8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=462&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/186431/original/file-20170918-13207-naako8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=462&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/186431/original/file-20170918-13207-naako8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=581&fit=crop&dpr=1 754w, https://images.theconversation.com/files/186431/original/file-20170918-13207-naako8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=581&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/186431/original/file-20170918-13207-naako8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=581&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An eye with myopia.</span>
<span class="attribution"><a class="source" href="https://nei.nih.gov/health/errors/myopia">National Eye Institute/National Institutes of Health</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>For children, eyeglasses or contact lenses move the focus back to the retina, and a <a href="https://nei.nih.gov/health/errors/myopia">clear image is formed</a>. The too-long eye measured from front to back cannot be “shrunk,” so refractive correction is then a lifelong necessity. In adulthood, surgery is an option.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/186433/original/file-20170918-15679-1701a2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/186433/original/file-20170918-15679-1701a2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=461&fit=crop&dpr=1 600w, https://images.theconversation.com/files/186433/original/file-20170918-15679-1701a2j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=461&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/186433/original/file-20170918-15679-1701a2j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=461&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/186433/original/file-20170918-15679-1701a2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=580&fit=crop&dpr=1 754w, https://images.theconversation.com/files/186433/original/file-20170918-15679-1701a2j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=580&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/186433/original/file-20170918-15679-1701a2j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=580&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A normal eye.</span>
<span class="attribution"><a class="source" href="https://nei.nih.gov/health/errors/myopia">National Eye Institute/National Institutes of Health.</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>But kids don’t always like wearing glasses, sometimes with good reason. It is harder to play sports in them. Swimming is nearly impossible, and kids tend to lose or break them.</p>
<h2>Myopia on the rise</h2>
<p>A worldwide epidemic of nearsightedness has been reported, associated with a combination of <a href="http://www.nature.com/news/the-myopia-boom-1.17120">genetic and environmental factors</a>. Besides creating the need to wear eyeglasses or contact lenses or to seek a surgical remedy, myopia can result in blinding eye diseases late in life, like retinal detachment or degeneration. </p>
<p><a href="http://iovs.arvojournals.org/article.aspx?articleid=2180601&resultClick=1">Risk factors</a> include having myopic parents. A debate about the influence of reading and other close work has flourished for more than a century.</p>
<p>The bad actor in the environment was always assumed to be near work, such as reading, sewing and now computer, video game and smartphone usage. That theory makes so much intuitive sense. The eye in childhood is naturally growing longer, even in normally sighted children. In a child developing myopia, the eye grows to focus on the frequently observed, near-viewing field. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/186046/original/file-20170914-24296-1oejy20.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/186046/original/file-20170914-24296-1oejy20.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=526&fit=crop&dpr=1 600w, https://images.theconversation.com/files/186046/original/file-20170914-24296-1oejy20.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=526&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/186046/original/file-20170914-24296-1oejy20.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=526&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/186046/original/file-20170914-24296-1oejy20.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=662&fit=crop&dpr=1 754w, https://images.theconversation.com/files/186046/original/file-20170914-24296-1oejy20.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=662&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/186046/original/file-20170914-24296-1oejy20.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=662&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artwork is from a school library, many years ago.</span>
</figcaption>
</figure>
<p>No less than <a href="http://galileo.rice.edu/sci/kepler.html">Johannes Kepler</a>, the astronomer and inventor who refined glass lenses for eyeglasses, was convinced that his poring over astronomical charts and calculations in the late 1500s was responsible for his nearsightedness. Kepler had it right when it came to the orbit of planets, but he was wrong about how the environment influences prescriptions for eyeglasses. The latest evidence says that near-work is not to blame for nearsightedness. </p>
<p>We studied this question for over 20 years in 4,979 children as part of the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study, funded by the National Eye Institute, in order to put near-work, computer use and watching television in their proper place – essential for study and recreation but <a href="http://jamanetwork.com/journals/jamaophthalmology/fullarticle/2206339">not an important factor</a> in whether a child will need glasses.</p>
<h2>Impressive differences for prevention</h2>
<p>If a child has two nearsighted parents, the hereditary genetic effects increase the child’s chances of needing glasses to about 60 percent, if time spent outdoors is low. </p>
<p>More time outdoors, about 14 hours per week, can nearly neutralize that genetic risk, <a href="http://iovs.arvojournals.org/article.aspx?articleid=2183997&resultClick=1">lowering the chances of needing glasses to about 20 percent</a>, the same chance as a child with no nearsighted parents claims. </p>
<p>A recent survey of papers from around the world, including Australia, England and <a href="http://www.aaojournal.org/article/S0161-6420(07)01364-4/fulltext">Singapore</a>, in the last decade align almost perfectly with what we published in 2007 from the Orinda Longitudinal Study of Myopia. </p>
<p>Parents may ask: What about children who already wear glasses? Does more time outside help already nearsighted children? </p>
<p>Unfortunately, we and others have found that time outdoors has little to no effect on how prescriptions change over time in children who are already nearsighted, although more study of this is ongoing. </p>
<h2>Enlightening theories</h2>
<p>So what’s so good about being outdoors for a child without glasses? There are several theories. </p>
<p>One is that children may exercise more when they are out of doors and that exercise is somehow protective. Another is that more ultraviolet B radiation from the sun makes for more circulating vitamin D, which somehow prevents abnormal childhood eye growth and myopia onset. Yet another is that light itself slows abnormal myopic eye growth and that outdoors, light is simply brighter. </p>
<p>The dominant theory is that the brighter light outside stimulates a release of dopamine from specialized cells in the retina. Dopamine then initiates a molecular signaling cascade that ends with slower, normal growth of the eye, which means no myopia. </p>
<p>Evidence from our work and from animal models of myopia indicate it’s the <a href="http://iovs.arvojournals.org/article.aspx?articleid=2127167">actual light exposure</a>, not just a decrease in the time spent reading because children are outdoors, that may work the magic.</p>
<p>There’s clearly much more to learn, but before you send your children out to run around the block, remind them to put on sunscreen and to wear sunglasses. Even as time outdoors might prevent the development of nearsightedness, parents will want to ensure they aren’t creating other skin and eye problems from ultraviolet light exposure.</p><img src="https://counter.theconversation.com/content/83693/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Karla Zadnik consults for Nevakar and received funding from the National Eye Institute, National Institutes of Health for research on myopia.</span></em></p><p class="fine-print"><em><span>Don Mutti receives funding from the National Eye Institute, National Institutes of Health. </span></em></p>Kids need to play outside for a number of reasons, but there may even be benefit for their eyes. Here’s how sunlight helps prevent nearsightedness, or myopia.Karla Zadnik, Dean, College of Optometry , The Ohio State UniversityDon Mutti, Professor of Optometry, The Ohio State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/733022017-03-01T10:01:47Z2017-03-01T10:01:47ZChildren need more violet light – here’s why<figure><img src="https://images.theconversation.com/files/158695/original/image-20170228-29942-9a1fq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/570981937?src=Ey6Cdjmq_4iwnTLbyH9_3w-1-4&size=medium_jpg">esthermm/Shutterstock.com</a></span></figcaption></figure><p>Short-sightedness is a global public health problem. Most people think of myopia (the medical term for short-sightedness) as an inconvenience because the blurred vision it causes is easily corrected with glasses or contact lenses. The problem is that a myopic eye is a longer eye and so the light sensitive part at the back of the eye is stretched. This can lead to a number of eye diseases in later life, such as <a href="http://www.sciencedirect.com/science/article/pii/S1350946212000444">glaucoma, maculopathy and retinal detachment</a>.</p>
<p>Experts are also concerned because the number of people with myopia is increasing. <a href="http://www.aaojournal.org/article/S0161-6420(16)00025-7/fulltext">Research</a> suggests that by 2050 it will affect half the world’s population. Myopia normally develops in children and increases in prevalence and amount during the teenage years. We know that about <a href="https://www.ncbi.nlm.nih.gov/pubmed/21762431">30%</a> of teenagers in the UK have myopia, and in some East Asian countries around <a href="https://www.ncbi.nlm.nih.gov/pubmed/25611765">80% </a> of teenagers have myopia. </p>
<p>The impact of these levels of myopia on all areas of society is enormous due to the cost of eye examinations, glasses and treatment of eye disease. The reasons why myopia develops are not fully understood; the prevalence has increased too quickly to be explained solely by genetics. </p>
<p>We know that our <a href="http://www.sciencedirect.com/science/article/pii/S1350946212000444">visual environment</a> also has a role in myopia development. Our lifestyle has changed significantly over the last 50 years, with greater time being spent indoors on <a href="http://pediatrics.aappublications.org/content/132/5/958">computers, tablets and smartphones</a>. It is the lack of time that children spend outdoors that seems to trigger myopia development. At Aston University, we are looking for ways to prevent myopia, or, if it has started, at ways to slow its progression.</p>
<h2>How to reduce the risk of myopia</h2>
<p>We know that spending greater <a href="https://www.ncbi.nlm.nih.gov/pubmed/27898443">time outdoors</a> (90 minutes a day) seems to reduce the risk of developing myopia. Why this works is not clear. The most recent research suggests that it may be the lack of visible violet light indoors that causes the problem and if we spend time outdoors in daylight we are exposed to ample <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5233810/">violet light</a>. The LEDs and fluorescent lights often used in our homes and schools contain little violet light, and violet light does not pass through materials such as the UV-protected spectacles and the glass in windows. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/158737/original/image-20170228-29911-c5wg1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/158737/original/image-20170228-29911-c5wg1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/158737/original/image-20170228-29911-c5wg1w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/158737/original/image-20170228-29911-c5wg1w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/158737/original/image-20170228-29911-c5wg1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/158737/original/image-20170228-29911-c5wg1w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/158737/original/image-20170228-29911-c5wg1w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Specially designed contact lenses can slow the progression of myopia.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/453500035?src=wbrMRUvyPZKxWdaMaVL9qQ-1-76&size=medium_jpg">Sergei Domashenko/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>If myopia has already developed, then we can slow progression by using different designs of contact lenses or with atropine eye drops. Atropine eye drops are normally used to temporarily stop the lens inside the eye from focusing and to make the pupil larger. A low dose of atropine eye drops also slows myopia progression without affecting pupil size and the ability to focus, though we are not sure why it works. </p>
<p>There are options for soft or rigid designs of contact lenses, and both types as well as correcting the blurred distance vision also alter the image in the periphery and this seems to control the growth of the eye. All these interventions slow the myopia progression by about <a href="http://www.aaojournal.org/article/S0161-6420(15)01356-1/fulltext">50%</a>. Spending more time outdoors may also help slow down progression of myopia in children. </p>
<p>We do not have all the answers to why and how myopia develops, but we do have ways we can slow down myopic progression. It is time that we stop just correcting the blurred vision in myopia and start actively managing and controlling it.</p><img src="https://counter.theconversation.com/content/73302/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicola Logan receives funding from CooperVision Inc for a clinical trial in myopia control. </span></em></p>Short-sightedness is a growing public health problem. Luckily, scientists are starting to find solutions.Nicola Logan, Senior lecturer, Aston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/618142016-07-17T11:28:55Z2016-07-17T11:28:55ZWhat’s behind the global rise in short-sightedness?<figure><img src="https://images.theconversation.com/files/130270/original/image-20160712-9292-15uki6e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/dl2_lim.mhtml?src=pp-same_artist-268599467--GUDkvrzV7DHL3mSblF0_Q-1&clicksrc=download_btn_inline&id=274787393&size=medium_jpg&submit_jpg=">Pincasso/Shutterstock</a></span></figcaption></figure><p>Over the last century, myopia (short-sightedness) has risen to epidemic proportions. In South-East Asia nearly <a href="http://bit.ly/1e4wE80">90% of school leavers</a> are now affected. In the West the figures are not as dramatic, but it appears to be <a href="http://archopht.jamanetwork.com/article.aspx?articleid=424548">similarly increasing</a>. We <a href="http://bit.ly/1FB04Yh">found</a> that nearly half of 25 to 29-year-olds are myopic in Europe and the rate doubled in those born in the 1960s compared with those born in the 1920s. </p>
<p>So what causes myopia? Why is it becoming dramatically more common? And what can be done to reduce the number of people developing the condition? </p>
<p>Short-sightedness usually develops in childhood, and occurs when the eye grows excessively long (“axial myopia”). This results in blurred distant vision that requires correction with glasses, contact lenses or laser-refractive surgery, at some inconvenience and expense. Also, being myopic increases the risk of sight-threatening diseases such as <a href="http://www.nhs.uk/conditions/Retinal-detachment/Pages/Introduction.aspx">retinal detachment</a> and myopic macular degeneration (thinning of the central part of light-detecting layer of the eye). </p>
<p>Increasing rates of myopia will lead to more blindness in the future.</p>
<h2>A few suspects</h2>
<p>While genes are important in predicting the risk of myopia, they alone cannot explain the recent epidemic. Risk factors for myopia include <a href="http://bit.ly/1FB04Yh">higher education</a>, <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0140419">prolonged near work</a>, <a href="http://iovs.arvojournals.org/article.aspx?articleid=2164363">living in cities</a>, and <a href="http://bit.ly/29X1dGx">lack of time spent outdoors</a>. </p>
<p>Near work, with prolonged reading at close focus, was previously thought to be the main culprit. But <a href="http://journals.lww.com/optvissci/Citation/2009/02000/Has_Near_Work_s_Star_Fallen_.3.aspx">reading time</a> does not appear to be a strong risk factor as it is not robustly associated with onset or progression of myopia in research studies. <a href="http://bit.ly/29vkmPs">Time spent outdoors</a> appears to be more important, but why it is protective is not entirely clear. Could it have something to do with bright sunlight, distant focus or even vitamin D production in the skin? We simply don’t know. The amount of time you spend in education appears highly significant; myopia risk is doubled if you have university education compared with leaving school at age 16. </p>
<p>But can these associations explain why myopia is becoming more common? There must be something in our modern lifestyles that is driving this epidemic. Humans have undergone numerous beneficial evolutionary adaptations to ensure we are well suited to our way of living. So are our eyes, and perhaps our brains, evolving to our urbanised lifestyles with prolonged computer work, intense education and less time outdoors? (We certainly don’t need to scan the horizon for our dinner any longer.) The answer is: probably not. Evolutionary adaptation happens over a much longer time frame, but it does make one wonder what effect modern life is having on our eyes.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/130273/original/image-20160712-9289-1cjpd10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/130273/original/image-20160712-9289-1cjpd10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/130273/original/image-20160712-9289-1cjpd10.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/130273/original/image-20160712-9289-1cjpd10.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/130273/original/image-20160712-9289-1cjpd10.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/130273/original/image-20160712-9289-1cjpd10.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/130273/original/image-20160712-9289-1cjpd10.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Don’t blame technology.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/dl2_lim.mhtml?src=7eiBAWUr6MsR5xjpBcvtEQ-1-7&clicksrc=download_btn_inline&id=182547512&size=medium_jpg&submit_jpg=">Tom Wang/Shutterstock</a></span>
</figcaption>
</figure>
<p>Technology, such as computers, tablets and mobile phones, are probably not to blame – the rising trend spans the 20th century, and the epidemic in urban Asia was apparent in the 1980s. Education levels have risen over the last century, but “highest educational level achieved” alone does not explain the trend. It may be that a risk threshold of close versus distance, indoors versus outdoors, has been reached. </p>
<h2>Still looking</h2>
<p>While we would not suggest higher education or near work should be limited to reduce myopia rates, changes in educational practices could help. For example, in studies in South-East Asia, where children often have intense after-school tuition, encouraging longer breaktime outside has led to reduced incidence of myopia. In one <a href="http://jama.jamanetwork.com/article.aspx?articleid=2441261">study in China</a>, primary school children who spent 40 extra minutes outdoors were 23% less likely to develop myopia (over a three-year period) than those who didn’t. So, perhaps a target of two hours outdoors a day should be considered.</p>
<p>Undoubtedly, we are seeing changes in the anatomy of our eyes as a direct result of modern life; there was less myopia when people lived a more rural existence and before the mass education of the latter half of the 20th century. There is a pressing need to understand how our environment, possibly in conjunction with our genes, increases the risk of developing myopia. We and others are <a href="http://www.nature.com/articles/srep25853">attempting</a> to <a href="http://www.nature.com/ncomms/2016/160329/ncomms11008/full/ncomms11008.html">answer</a> these<a href="http://iovs.arvojournals.org/article.aspx?articleid=2336642"> questions</a>, with the hope of reducing the growing burden of myopia in the future.</p><img src="https://counter.theconversation.com/content/61814/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Hammond is the Frost Chair of Ophthalmology and was previously awarded a NIHR Senior Research Fellowship . </span></em></p><p class="fine-print"><em><span>Katie Williams receives funding from a MRC Clinical Research Training Fellowship. </span></em></p>Genes are important in predicting the risk of myopia, but they alone cannot explain the epidemic.Chris Hammond, Frost Professor of Ophthalmology, King's College LondonKatie Williams, MRC Clinical Research Fellow (Ophthalmology), King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/445952015-07-21T03:05:03Z2015-07-21T03:05:03ZWe can prevent an epidemic of short-sighted kids with more time outdoors<figure><img src="https://images.theconversation.com/files/88806/original/image-20150717-13766-hltsqe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bright light outdoors stimulates the release of the retinal transmitter, dopamine, which has a protective effect. </span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/kellypietphotography/7066561727/">Kelly Piet/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p><a href="http://www.nature.com/news/the-myopia-boom-1.17120">Myopia</a>, or short-sightedness, is a condition in which distant objects appear blurred, but closer objects can usually be seen in sharp focus. </p>
<p>Its biological basis is an eye that, during childhood, has grown too long for its optical power. The focal plane for images of distant objects ends up in front of the retina, causing out-of-focus perception. </p>
<p>Fortunately, mild to moderate levels of myopia can be readily corrected with spectacles, contact lenses or laser surgery, which flattens the front of the eye. </p>
<p>But prevention is better than correcting the optical defocus. Fortunately, spending <a href="http://www.sciencedirect.com/science/article/pii/S0014483513001061">more time outdoors</a> may decrease children’s chances of developing myopia. </p>
<h2>Finding the cause</h2>
<p>Myopia was once regarded as almost totally genetically determined. But its prevalence has increased spectacularly in urban mainland China, Hong Kong, Taiwan, Singapore, Japan and South Korea, where 80-90% of those completing high school are now short-sighted. This is up from 20-30% only two generations ago. </p>
<p>Since gene pools do not change that fast, these massive changes must be due to environmental change.</p>
<p>In 2005, <a href="http://www.sciencedirect.com/science/article/pii/S1350946204000564">we comprehensively reviewed</a> the research on myopia and found a correlation with education. (This was not a particularly novel insight; such a link was postulated as far back as Kepler in 1604.) We found <a href="http://onlinelibrary.wiley.com/doi/10.1111/opo.12040/abstract;jsessionid=43332C501AAB959B24C801B4281FC3BC.f03t01?userIsAuthenticated=false&deniedAccessCustomisedMessage=">locations</a> with a high prevalence of myopia were all top performers in surveys of international educational outcomes. </p>
<p>Fortunately, not all high-performing locations, Australia among them, showed a high prevalence of myopia. This shows that high educational outcomes do not necessarily <em>lead</em> to myopia. </p>
<p>We also hypothesised that all human population groups had a tendency to develop myopia under particular environmental conditions. Indeed, <a href="http://archopht.jamanetwork.com/article.aspx?articleid=424548">North America</a> and <a href="http://www.aaojournal.org/article/S0161-6420%2814%2900364-9/abstract">Europe</a> have seen growing rates of myopia, although they are still nowhere near as high as in East and Southeast Asia.</p>
<h2>Prevention is the key</h2>
<p>A common cutoff for high myopia is -5 diopters. This means vision is blurred beyond 20cm from the eyes. Such severe or high myopia increases with age and <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2812%2960272-4/abstract">can lead to</a> visual impairment that can’t be corrected. </p>
<p>The prevalence of high myopia has now reached 20% in young adults in East and Southeast Asia, which foreshadows major increases in visual impairment and blindness as these young adults age. So prevention of myopia has become crucial, particularly for East and Southeast Asia. </p>
<p>Three clinical trials in East Asia <a href="http://www.sciencedirect.com/science/article/pii/S0014483513001061">have shown</a> that increasing the amount of time children spend outside at school reduces the risk of myopia. Experimental studies suggest that bright light outdoors stimulates the release of the retinal transmitter, dopamine, which has a protective effect. </p>
<p>Australia has naturally low levels of myopia with a lifestyle that emphasises outdoors activities. Young children report spending two to three hours a day outside, not counting time outdoors at school. However, there are formidable barriers to achieving this benchmark in locations where spending time outdoors is seen as a distraction from study.</p>
<p>Policy responses must therefore also aim to slow the progression of myopia, the phenomenon in which mild to moderate myopia becomes more severe during childhood. There is currently controversy over whether time outdoors slows progression, but strong seasonal effects on progression suggest that it may. </p>
<p>School regimes which give a sufficient place to time outdoors may reduce both the onset and progression of myopia. These school-based interventions will need to be supplemented by clinical interventions, such as the use of <a href="https://www.medicines.org.uk/emc/medicine/29117">atropine eye drops</a>. </p>
<p>Recently, the <a href="http://www.brienholdenvision.org/">Brien Holden Vision Institute</a> released projections on the future prevalence of myopia and high myopia, based on these well-documented trends. While projections are inevitably based on uncertain assumptions, they confirm that a critical situation could emerge in the next few decades in more than just East and Southeast Asia, if preventive measures are not put in place.</p>
<p>Commentators have recently emphasised the role of digital devices, and specifically tablet computers, in the emergence of an epidemic of myopia. In Taiwan, this has prompted <a href="http://kotaku.com/taiwan-to-fine-parents-of-kids-who-spend-too-much-time-1681762979">limits</a> on the use of such devices by young children. </p>
<p>However, a simple historical perspective suggests that their role is minor. The prevalence of high myopia in young adults in Singapore and Taiwan was already high by the early 1990s, well before digital devices became common. The world wide web was not launched until 1993, and smart phones and tablets were not developed until just a few years ago. These devices cannot have been causal.</p>
<p>There is, in fact, no evidence that digital device are harmful in themselves. They may add to “near” workloads, or lead to children spending less time outdoors, which could exacerbate current problems. But the root causes of the myopia epidemic lie in the imbalance between educational pressures and the amount of time children spend outdoors in bright light. </p>
<p>The epidemic needs to be addressed at this level, through school-based preventive interventions, combined with a more active preventive approach in clinical practice.</p><img src="https://counter.theconversation.com/content/44595/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Morgan and Kathryn Rose have received funding from the National Health and Medical Research Council.</span></em></p><p class="fine-print"><em><span>In addition, Kathryn Rose has received funding and acted as a consultant to the World Health Organisation.</span></em></p>Myopia, or short-sightedness, is a condition in which distant objects appear blurred, but closer objects can usually be seen in sharp focus.Ian Morgan, Visiting Fellow, Research School of Biology and Distinguished Visiting Fellow, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, CHina, Australian National UniversityKathryn Rose, Professor of Orthoptics, Graduate School of Health, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/282292014-06-23T13:54:08Z2014-06-23T13:54:08ZUnderstanding the mechanics of the eye could help treat degenerative disease<figure><img src="https://images.theconversation.com/files/51782/original/w88rcf79-1403276471.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Insight into the eye.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/e-coli/8363280904/sizes/l/">Latente</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>When people think about biomechanics in health it’s more than likely they will think of treatments related to the human musculoskeletal system, such as treating knee injuries or osteoarthritis. But this field of research, which involves understanding biological systems through mechanics, has many more applications, including its use in treating common and serious eye conditions.</p>
<p>The eye is a pressurised vessel and many processes within it can be understood with the principles from solid and fluid mechanics. Common eye disorders such as glaucoma and myopia (near-sightedness) are associated with profound biomechanical changes. For example, with myopia the region at the back of the eye globe becomes elongated and mechanically weaker.</p>
<p>One of my research interests in ocular biomechanics is <a href="http://www.moorfields.nhs.uk/condition/keratoconus">keratoconus</a>, a progressive, degenerative disease that is now considered to be a major clinical problem worldwide, affecting <a href="http://www.nature.com/srep/2014/140409/srep04608/full/srep04608.html">up to 600 people per 100,000</a>. Although this could be considered relatively rare, the condition appears to be on the rise. </p>
<p>Keratoconus poses important biomechanical questions because as the disease progresses the cornea becomes thinner, cone-shaped and mechanically weak. This leads to increasing myopia and astigmatism, and in later stages the transparency of the cornea can be lost due to scarring. Ultimately, a corneal transplant may be required due to the scarring and extreme thinning of the cornea.</p>
<p>Interest in keratoconus is not just an academic pursuit, but also personal. My brother and I were recently diagnosed with a mild form of the disease and I was recently involved <a href="http://www.iovs.org/content/54/8/5273.long">in a study</a> which looked at measuring mechanical changes that can be induced in the cornea. This exciting and relatively new clinical procedure uses riboflavin (vitamin B2) and ultraviolet-A (UVA) light irradiation to halt progression of the disease. </p>
<p>The cornea is composed of a regular matrix of collagen fibres which provide mechanical support. These fibres are strengthened by inter-molecular bonds or cross-links. In keratoconus, it is thought that these cross-links are abnormal and reduced, which results in a bulging shape of the cornea and the associated thinning and mechanical weakness.</p>
<p>The riboflavin/UVA procedure aims to induce additional cross-links in the cornea. It not only increases the stiffness and strength of the cornea but has an additional benefit as it also flattens the cornea, reducing myopia and astigmatism. There are still many unanswered questions regarding this procedure, such <a href="http://www.revoptom.com/continuing_education/tabviewtest/lessonid/108520/">as the safety</a> and efficacy of high intensity UV treatments that are now being developed, which we hope to tackle in future research.</p>
<p>I am also interested in increasing our understanding of the structure and properties of the sclera, or the white of the eye. The sclera is not just an inert casing that holds the eye together, but it also has an important biomechanical role in healthy eye function.</p>
<p>People with myopia see distant objects as blurred because images are focused in front of the retina rather than on it due to an abnormal shape of the eyeglobe. Myopics have a weaker and elongated sclera. Compared to the cornea, the sclera has a much more complicated structure and is less extensively studied. The sclera is another area where biomechanics could help with answers.</p>
<p>Historically, there has been less interest in ocular biomechanics research compared to other disciplines in the biomechanics field although there is now more notice. Over the last decade, the development of innovative computational and experimental techniques have allowed scientist to accurately determine the mechanical behaviour of the eye and helped to build medical devices to improve the management and treatment of a number of ocular conditions. For example, such research has led to significant developments in the tonometry devices that are used in opthalmology clinics to measure fluid pressure within the eye. With the current international drive in this area, there will ultimately be further progress in tackling challenging eye diseases with biomechanics research.</p><img src="https://counter.theconversation.com/content/28229/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Riaz Akhtar does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>When people think about biomechanics in health it’s more than likely they will think of treatments related to the human musculoskeletal system, such as treating knee injuries or osteoarthritis. But this…Riaz Akhtar, Lecturer in Biomedical Engineering, University of LiverpoolLicensed as Creative Commons – attribution, no derivatives.