A recent research article published on the website of TIME magazine, a U.S. publication, states that the high prevalence of myopia among school-aged children in Asia is likely due to excessive time spent indoors studying and insufficient exposure to natural light.
The myopia rate among adolescents in Asian countries is 2–3 times higher than in the UK
In Asian countries such as China, Japan, South Korea, and Singapore, the myopia rate among adolescents exceeds 90%, whereas in the UK this rate is only 20% to 30%. For a long time, it was widely believed that myopia was primarily caused by genetics. However, researchers led by Ian Morgan of the Australian National University pointed out through data analysis that environmental factors have a significant impact on the development of myopia. For example, in Singapore, the myopia rates of three different ethnic groups—the Chinese, Malays, and Indians—have all increased similarly since 1996.
Researchers believe that common environmental factors are behind the rise in myopia rates. Asians who have emigrated to other parts of the world also support this view: Chinese adolescents in Australia, who are exposed to more sunlight, have lower myopia rates than their peers living in East and Southeast Asia. Of particular concern is that about 10% to 20% of Asian school-aged children suffer from high myopia, which puts them at risk of developing more serious eye conditions or even blindness in adulthood.
More time spent studying indoors is positively correlated with higher myopia rates
Morgan believes that the immense academic pressure and competitive environment cause students to spend too much time studying indoors with little exposure to natural light. In fact, the countries with the highest myopia rates in Asia are also those that perform the best in education and academics.
Myopia occurs when the front-to-back length of the eyeball is too long, causing the image of distant objects to focus not on the retina but in front of it, resulting in blurred vision at a distance. Animal studies have shown that if the field of vision is limited to a small area during early growth and development, it can lead to elongation of the eye axis and subsequent myopia. Scientists believe that the neurotransmitter dopamine plays an important role in shaping the structure of the eyeball. Exposure to natural light promotes dopamine production, which prevents excessive elongation of the eye axis and thereby helps prevent myopia. Experiments conducted on rats and monkeys have also confirmed this theory.
Ensure your child gets outdoor activity – “Tiger Moms,” don’t be shortsighted
Although it is still unclear when human eyes stop growing, Morgan says that because symptoms of myopia often appear early among adolescents in Asia, the eye axis continues to elongate during the growth period, worsening the degree of myopia. Moreover, apart from wearing corrective lenses, there are currently no effective methods to prevent or treat myopia. Therefore, scientists recommend that parents of Asian schoolchildren, especially those ambitious “Tiger Moms,” should ensure their children have regular breaks. If children can spend one to two hours outdoors every day and enjoy ample sunlight, the situation could improve significantly.
