There may be a simple way to protect children’s eyesight, British doctors report: send kids outside to play more often.
An analysis of eight studies looking at what may prevent myopia points to time spent outdoors, Anthony Khawaja of the University of Cambridge reported on Monday to a meeting of the American Academy of Ophthalmology.
“For each additional hour spent outdoors per week, the chance of myopia dropped by approximately two percent,” the academy said in a statement. “Nearsighted children spent on average 3.7 fewer hours per week outdoors than those who either had normal vision or were farsighted.”
The results seem to be produced simply from being outdoors, the AAO said. It’s not clear whether simple exposure to natural sunlight is the cause, or perhaps time spent focusing on distant objects.
Scientists have long been interested in why myopia rates are rising in the United States and elsewhere. A quarter of American children and adolescents currently suffer from refractive errors such as myopia, farsightedness, and astigmatism, according to Centers for Disease Control data.
Some scientists have speculated that an increase in ‘near work’—like staring at a computer screen or reading a book-- might be responsible for the rise in nearsightedness. Two studies examined by the British team, however, failed to find a correlation between more time spent outdoors and less time performing near work.
“Increasing children’s outdoor time could be a simple and cost-effective measure with important benefits for their vision and general health,” Khawaja said in a statement. “If we want to make clear recommendations, however, we’ll need more precise data.”
Researchers next need to consider “what aspect of outdoor activity is protective for myopia,” Khawaja said in an interview. “Is it less close work? Is it UV light exposure? Is it more physical activity?” The AAO statement noted that another question to answer is “whether boosting outdoor time might stop nearsightedness from getting worse.”