Here’s a quirky idea: computer and television screens can damage eyes because the lack of sunlight can reshape the eyes and impair vision over time, according to a growing community of researchers. A new article in the New York Times cites a study published recently in the Journal of the American Medical Association (JAMA Ophthalmology) that offers an explanation for the growing prevalence of myopia, or nearsightedness, especially in children and young adults.
Nearsightedness is a condition in which the eyeball is longer than normal, altering the angle at which light meets the eye, which can cause problems for people when focusing on faraway objects. It is a condition that really illustrates the debate between “nature and nurture” -- even if you develop it as a child, nearsightedness can progress as you become an adult depending on a complex calculus of genetics factors and the environment.
Volunteers were given eye exams and asked how much time they spent outside during their childhood. Researchers found a strong correlation between “current eyesight and lifelong exposure to sunlight.” It’s important to remember that this particular study was a survey and not an experiment where the researchers imposed certain conditions to, say, measure the effect of sunlight exposure on prescriptions for eyeglasses. The researchers observed a trend where those who had been exposed to the most sun as teenagers were less likely to be nearsighted in middle age.
The link is not necessarily a causal one, but the implications are clear. Despite the fact that excessive exposure to sunlight certainly poses its own dangers, such as the risk of skin cancer, a healthy amount of exposure can really be positively correlated to multiple aspects of health, including vision. The observed correlation between sun exposure and healthy vision only strengthens the case against excessive exposure to screens and monitors indoors. Moderation is key, but it looks as if we are still unlocking the many benefits the sun has to offer.