Outdoor light slows childhood myopia


Myopia, also called nearsightedness, describes the condition in which the observer cannot clearly see objects that are far away. Instead, the person is only able to distinctly see things that are located in close proximity. Though the explanations behind myopia are just as varied as they are inconclusive, blurry vision is usually caused by light entering the retina incorrectly.

Environmental factors, such as spending time behind computer screens or subjecting oneself to close-distanced reading and other visual work have long been suspected contributors to nearsightedness. Other suspects include genetic inheritance and diabetes, although no studies have been able to completely verify any certain factor.

Myopia can cause fatigue, dizziness and headaches. If left to worsen, it can eventually give way to blindness. To cope with myopia, users often wear eyeglasses or contact lenses to help readjust their vision. More recently, people have been able to opt for laser surgery or other reparative procedures to reduce or eliminate myopia, though these solutions are more expensive. While eyeglasses may cost around $100 to $300 on average, laser eye surgery can cost up to $2,500 for a single eye.

With almost a third of U.S. citizens suffering from myopia, according to a 2008 study conducted by the National Eye Institution, the panic behind such a large percentage became quite worrisome. Brien Holden, a leading optometrist, predicts that by 2050, at least 50 percent of the world will be nearsighted.

According to a recently published study, however, breaks have been made toward tackling the increase of myopia all over the world. The researchers behind the paper were able to conclude that exposing children to outdoor light, optimally for two hours, will help slow myopic progression in young children.

The study included 101 children between the ages of 10 and 15. Fourty-one children had mild or slight myopia while 60 were not affected by it. Each child was given a sensor device, worn on the wrist, which measured the visible light in his or her environment. During the 18-month period in which the study was conducted, the children wore the device twice for 14 days. To compensate for outdoor light changes due to changing seasons, the two-week periods took place in six-month intervals.

At the end of each 14-day period, the axial length of the child’s eye was measured for changes. Researchers also required guardians to fill out questionnaires to clarify the children’s use of “sun protection strategies,” and other variables.

The study concluded that children who were nearsighted were often exposed to less daily outdoor light than their non-myopic counterparts. Although the difference was not staggering, these same myopic children also spent, on average, more time on “nearwork,” as opposed to outdoor activities.

In the 18-month period, children exposed to low daily light suffered around a 0.16 change in axial length while children exposed to moderate and high daily light exposure suffered no more than around a 0.6-axial-length increase. Interestingly enough, especially in myopic children, those who were exposed to high daily light suffered more axial length increase than those with moderate daily light exposure, although it did not rival the increase for those exposed to low light on a daily basis.

The findings of this study mark the beginning of the long hurdle against myopia and, possibly blindness. For the first time, we may be able to look at myopia and its side effects as a diminishing source of discomfort in our future.

Although coping with myopia is the only option for some people, there is now means to begin effectively slowing its development and progression in younger people. In addition to incorporating the right amount of ambient light, people, regardless of their vision, should be scheduling annual eye exams to monitor and potentially improve their eye health.