Parents often ask about electronic devices and their effects on vision, as many children are spending a significant part of their day on smartphones, tablets, e-readers, laptops, etc. Parents are often concerned that increased screen usage may make their child nearsighted (myopia is the medical term) and result in their child needing glasses.
These parental concerns are particularly important today as a National Eye Institute (NEI) study has found that the prevalence of myopia in the United States increased 66 percent between 1971-1972 and 1999-2004. Although the NEI report did not address the exact causes of myopia, the increased incidence may mean that children might need glasses at younger ages and that the degree of the correction may be greater.
Myopia is a focusing mismatch in which light rays entering the eye are focusing in front of the retina instead of on the retina (the retina is often described as the film in a camera). This can happen when the eyeball is too long or the cornea curves too much. When images enter the front of the eye and focus in front of the retina, distant objects are blurry while near objects appear clearly. In most cases this is a progressive condition, worsening over a period of years before leveling off. Myopia is typically corrected with glasses or contact lenses. There are also treatments aimed at slowing the progression of myopia, like bifocals, prescription eye drops, or different types of contact lenses. Not every treatment works for every person and unfortunately, none of them make the myopia go away.
Research has shown that near-work is not likely the primary cause of nearsightedness though it may play a role. Research does support a genetic factor: if one of your parents is myopic, your chance of being nearsighted increases. This chance further increases if both of your parents are nearsighted.
Environmental factors are likely related as well. For example, research does support an inverse correlation between time spent outdoors and the incidence of myopia – i.e., more time spent outdoors in natural sunlight is associated with lower rates of nearsightedness. We don’t know why more outdoor time has this effect. It may be exposure to sunlight, it may be focusing the eyes for long distances, it may be something else or a combination of things. But the idea that focusing far away could be reducing the incidence of children who develop myopia makes us wonder if excessive near-work is a factor in increasing the incidence of myopia. Is all this time spent with our gadgets a factor? We wonder, but the truth is that we do not know as far as scientific data are concerned.
If you are concerned and your child has not had a formal eye exam within a year, then a visit to an eye doctor is a good idea. Our eye doctors will work with you and your child and discuss treatments and plans in more detail. When in doubt, have one of our eye doctors check it out.