A group of Chinese researchers found that children who spend more time outdoors have a lower risk of developing myopia or nearsightedness later on.
According to the study’s background information, about 30 percent of Americans and 40 percent of Asians struggle with the eyesight condition. The popular belief states that nearsightedness is caused or made worse by reading or working in poor light. Past studies had shown that family history, genetics and some childhood activities may be also responsible for myopia.
But Chinese scientists planned to learn whether the studies showing that playing outside may influence vision in children were correct.
The study involved nearly 2,000 first-graders from a dozen of schools in Guangzhou, South China. Half of the schools’ headmasters agreed to extend recess and keep kids outside longer daily. The rest of the schools agreed to allow researchers measure the eyesight of their students, but didn’t make any changes in recess.
The experiment was carried out for three years. After three years, 40 of the first-graders in the control group developed nearsightedness, while only 30 percent of kids who stayed outside longer during recess developed the condition.
On the other hand, scientists have hoped for a more striking result. They said that they were inspired to conduct the study by a Taiwanese team that locked kids outside for 80 minutes on a daily basis and observed a 50 percent reduction on nearsightedness rates in those children.
During the recent study, which was published in the Journal of the American Medical Association, volunteers were kept outdoors for an extra 40 minutes on a daily basis during the 9-month school year.
Dr. Mingguang He, lead author of the study, wrote in the research paper that his team obtained only a 9.1 percent reduction in the incidence myopia rates, and a 23 percent reduction following the three-year period. But the findings were below expectations.
On the other hand, the research team believes that the benefits of staying outside for kids may be wider. The kids that did develop myopia after three years may have also benefited from the experiment because if it weren’t for the time spent outside they might have developed a more severe type of myopia.
Additionally, scientists noted that most parents didn’t encourage their kids to play outside after school, as researchers suggested. If parents had followed the advice, their kids might have benefited more form the mix of sunlight and outdoor activity. The team noted that in a previous study kids who were asked to exercise indoors didn’t see their myopia rates decrease. So, physical exercise is not the only factor that can improve their vision, researchers suggested.
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