If you needed another reason to pry your kids away from the TV and video games: More time outdoors may reduce their risk of nearsightedness, according to a new analysis of previous studies.
The researcherslooked at data from eight studies on outdoor time and nearsightedness in children and adolescents. The studies involved a combined total of 10,400 participants.
The results showed that nearsighted kids spent an average of 3.7 fewer hours outdoors per week than children who either had normal vision or were farsighted. The researchers also found that for each additional hour that a child spent outdoors per week, their risk of developing nearsightedness dropped by about 2 percent.
Playing outdoors, or just spending time away from the boob tube, may have broad benefits for kids, according to a policy statement released last week by the nation's largest group of pediatricians. The group says children under 2 should avoid watching TV as much as possible and instead should play.
"Increasing children's outdoor time could be a simple and cost-effective measure with important benefits for their vision and general health," study researcher Anthony Khawaja of the University of Cambridge said in a statement.
Increased exposure to natural light as well as more time spent looking at distant objects — which kids are more apt to do outside than indoors — may play roles in lowering children's risk of developing nearsightedness, the researchers speculate.
"If we want to make clear recommendations, however, we'll need more precise data," Khawaja said. "Future, prospective studies will help us understand which factors, such as increased use of distance vision, reduced use of near vision, natural ultraviolet light exposure or physical activity, are most important."
Also known as myopia, nearsightedness is the most common cause of visual impairment worldwide. Its prevalence has been increasing in recent decades, especially in East Asian areas, such as China, Japan and Singapore, according to the National Institutes of Health.
The findings were presented on Oct. 24 at the 115th Annual Meeting of the American Academy of Ophthalmology.