Does Playing Outdoors Benefit Kids' Vision?
Study Shows Children Who Play More Outside Are Less Likely to Be Nearsighted
WebMD News Archive
Oct. 25, 2011 (Orlando, Fla.) -- Children who spend more time outdoors may be less likely to suffer from nearsightedness, a study shows.
In nearsightedness, objects in the distance appear blurry and out of focus.
Researchers who pooled the results of eight previously published studies involving more than 10,000 youngsters found that each additional hour spent outdoors during the week decreased the risk of developing nearsightedness (myopia) by 2%.
"This translates to about a 13% reduced chance of developing nearsightedness per extra hour per day of physical activity outdoors," says researcher Anthony Khawaja, MBBS, an ophthalmologist at the University of Cambridge, U.K.
The study also showed that children who were nearsighted stayed indoors about four hours more per week than children who had normal vision or were farsighted, in which nearby objects appear blurry.
"Increasing children's outdoor time could be a simple and cost-effective measure with important benefits for their vision and general health," Khawaja says. "If we want to make clear recommendations, however, we'll need more precise data."
He presented the findings here at the annual meeting of the American Academy of Ophthalmology (AAO).
Explaining the Role of Outdoor Activity
The researchers were unable to determine the impact of any specific activity on reducing the risk of nearsightedness.
Why being outdoors might protect against nearsightedness is the big question, AAO spokeswoman Anne Sumers, MD, tells WebMD. Sumers is an ophthalmologist in Ridgewood, N.J.
"Is it the physical activity itself? Is it because of exposure to ultraviolet light outside? Is it because they’re spending less time doing close reading? Or is it something else altogether," Sumers asks.
Khawaja agrees. Most of the studies took into account some potential risk factors that could affect the results -- usually age, family history of nearsightedness, and some measure of close activities like reading -- but not all, he says.
The timing of the rise in nearsightedness coincides with the explosion in computer and cell phone use, Khawaja says. At the same time, kids are less likely to engage in the outdoor games of their parents' youth, such as touch football, jump rope, or capture the flag.