Time Outdoors Reduces Nearsightedness Risk
October 25, 2011 by UPI - United Press International, Inc.
ORLANDO, Fla., Oct. 24 (UPI) — The more time children spend outdoors, the less risk they have for myopia, or nearsightedness, but British researchers say they aren’t sure why.
Dr. Anthony Khawaja and Dr. Justin Sherwin, both of the University of Cambridge, used data for the analysis from eight studies involving 10,400 participants, on outdoor time and myopia in children and adolescents.
Sherwin’s team found for each additional hour per week spent outdoors, the risk of myopia dropped by approximately 2 percent. The researchers found nearsighted children spent on average 3.7 fewer hours per week outdoors than those who either had normal vision or were farsighted.
The researchers said the reasons behind the findings are not clear, but the protective effect appears to result from simply being outdoors rather than performing a specific activity such as physical activity.
Myopia has risen significantly in the United States and other countries since the 1970s — in parts of Asia, more than 80 percent of the population is nearsighted, the researchers said.
The findings were presented at the 115th annual meeting of the American Academy of Ophthalmology in Orlando, Fla.