Why Are So Many Asians Nearsighted?
Time magazine features an article entitled, "Why Up to 90% of Asian Schoolchildren Are Nearsighted." According to a study published in the Lancet by Ian Morgan of Australian National University, up to 90% of young adults in China, Taiwan, Japan, Singapore, and South Korea are nearsighted--compared with only a 20 to 30% rate of myopia in the UK.
These East Asian countries with high myopia rates are also those found at the top of the international rankings of educational performance. Scientists are concerned that the high prevalence of myopia in Asian children is associated with increased educational pressures and lifestyle changes, which have reduced the amount of time that children spend outside.
Myopia is the result of elongation of the eyeball, which leads to blurry images at a distance. Scientists think that exposure to bright outdoor light increases the levels of the neurotransmitter dopamine in the eye, which may prevent elongation of the eyeball. The recommendation for prevention of myopia? 2 to 3 hours of outdoor sunlight each day.