Outdoor play could reduce kids' nearsightedness
More time spent outdoors could mean a reduced rate of nearsightedness for children and adolescents, according to an analysis by Cambridge University researchers.
They found that instances of myopia — or nearsightedness — occurred less frequently in children who spent more time outdoors, suggesting increased exposure to natural light and more time spent looking at distant objects may be key factors.
Researchers found that the chance of myopia decreased by two per cent in children for each additional hour they spent outdoors per week.
"Increasing children's outdoor time could be a simple and cost-effective measure with important benefits for their vision and general health," said Dr. Anthony Khawaja of the University of Cambridge.
"If we want to make clear recommendations, however, we'll need more precise data. Future, prospective studies will help us understand which factors — such as increased use of distance vision, reduced use of near vision, natural ultra violet light exposure or physical activity — are most important."
Two of the studies examined whether the children who spent less time outdoors spent more time studying or playing computer games but there was no evidence of that connection.
There were 10,400 participants included in the data taken from eight selected studies.
Khawaja said another question that should be considered now is whether increasing the amount of time children spend outside will also stop nearsightedness from getting worse.
Khawaja referred to a Chinese study of 80 nearsighted children between the ages of seven and 11. Forty children were assigned to spend more than 14 hours outdoors per week and less than 30 hours doing near work.
At the end of the two-year study, the 40 children in the controlled group who spent more time outside were less nearsighted than the others.
There are more cases of myopia in many countries including the United States than in the 1970s. In parts of Asia, as much as 80 per cent of the population is nearsighted.
Khawaja will present the analysis — which was led by Dr. Justin Sherwin — Monday at the 115th Annual Meeting of the American Academy of Ophthalmology in Orlando, Fla.