Why Are 90% of Asian Schoolchildren Nearsighted? From Doing What You're Doing Now

By Sarah Zhang | May 12, 2012 8:40 am

kid with glasses

With glasses, contacts, and LASIK surgery, most of us nearsightedness folks don’t have to worry about squinting at the blackboard anymore. But the sheer prevalence of nearsightedness, or myopia, among Asian schoolchildren (in Singapore, China, Taiwan, Hong Kong, Japan, and Korea) is stunning: 80 to 90% according to a recent review in the journal Lancet. In comparison, that number is just 20 to 30% in the UK. Myopia has also been on the rise in both Asia and Europe over the past few years.

While there are genes linked to myopia, its rising prevalence in both continents points to environmental causes. Namely, kids are spending more time hunched over screens and books instead of playing outdoors. In myopia, light coming into the eye can no longer focus at the retina because the eyeball has become too long. A body of research in humans and animals suggest that reading at close distances and lack of bright sunlight could cause elongated eyeballs.

In Singapore, myopia has shot up in the last 30 years among all three major ethnic groups—Chinese, Indian, and Malay—which highly suggests a environmental cause. Singaporean schoolchildren who read more than two books per week were also more likely to have myopia. How one reads physically, may have an impact too: ultra-orthodox Jewish boys, who study the Torah intensely and at a close distance while swaying have higher myopia numbers than the girls, who don’t. A study on students of Chinese ancestry in the Singapore and Australia has also found correlations between among of time spent outdoors and lower rates of myopia. Together, these observational studies suggest that high myopia rates in Asian schoolchildren are likely related to their intense educational systems.

myopia graph

Animal studies provide some clue into why bright sunlight could actually protect eyes from myopia. While UV rays in sunlight is harmful, the unique intensity of non-UV light from the sun stimulates dopamine release, which affects eye growth according to studies in chicks and monkeys. A recent study in tree shrews suggest that especially bright fluorescent lights could stave off myopia too.

So for people trying to avoid glasses (but that’s totally geek chic now, right?), going outside could be a bright idea. Just don’t be squinting at your phone the whole time.

[via TIME]

Images via Shutterstock / Realinemedia and Ian Morgan/Lancet 

CATEGORIZED UNDER: Health & Medicine
  • Prem Das

    The enviromental cause to high levels of myopia is living and working in artificial light.

    Please observe that those who work outside in natural light and toil in the sun, like mechanics, panel beaters, and construction workers etc., etc., enjoy good eyesight well into their dotage and further.

    Time someone did some studies.

  • mike

    Since reading isn’t going anywhere we will adapt

  • http://kforcounter.blogspot.com Cody

    I recall a study from several years ago in which it was suggested that a gene regulating eyeball growth was causing many cases of nearsightedness. The hypothesis was that in nature the gene would have correctly caused the eyeball to continue growing under conditions in which it did not focus properly, but that in modern societies where reading starts in childhood while the body is still developing, incorrectly triggers the gene into continued growth. It mentioned a study showing the incidence of nearsightedness jumped after the introduction of public education to Inuit societies.

  • Matt

    So I wonder if this means that an increase in reading could directly result in an increased amount of success in higher education in those areas (I think that would make sense)? And taking that one step further, what would the data show for countries like the US, where our education system is continually, and rightfully, criticized? It would also be interesting to see how the increase in myopia is related to social networking patterns, since, as stated, it is implied that children are spending less time outside with friends and more time alone with books and computers.

  • Jay Fox

    The western diet plays a significant role. As we continue to refine all the vitamins and minerals from our food supply, malnutrition limits proper development. Lack of sufficient vitamin A has been shown to promote myopia.

    Those Inuits were not only introduced to public education, but the western diet at the same time. Any discussion leaving out the role of proper diet is incomplete.

  • Vince

    Absolutely , would I like a geneticist to weigh in here , for instance in the Inuit study how would any one really know whether one was near sighted when the culture had no mechanism of reporting it until the study came along ? interbreeding with more genetic variables is the reason for increased occurrences ,My suspicion ,in Asian societies there was a starting point of a tendency of near sightedness ,enhanced by social mobility with the genetic variability sky rocketing the number of near sighted births in a shorter period of time , yes the additional factors are valid but only augment the already established genetic fact of near sightedness

  • Red the Fister

    @Jay Fox

    You do realize that the only reason i’m posting this is because you come across as a shill for the Free Range/Organic Foods “Industry.”

    Yes, our diets suck. Yes, overly refined foods are not nearly as healthful as un-refined foods. Yes, even on a free-range organic diet it is impossible to attain “perfect” nutrition: there are simply far too many nutrients that come from far too wide a range of foods for us to consume all of them daily without supplementation.

    that said, i take issue with, “Those Inuits were not only introduced to public education, but the western diet at the same time. Any discussion leaving out the role of proper diet is incomplete.”

    Correlation does not equal Causation.
    Site your References. Preferably from a respected, peer-reviewed journal.

  • Nik Edmiidz

    Or you could try not reading and using TTS to consume text-content, like blind people do… I hate reading…

  • http://www.sionsafety.com Simon Sanjaya

    Since I was a yunior high school I did a bit massage around my eyes after a long time reading. So my eyes were normal until I graduated from university. Several years ago I invented THERAPY RUN, a little part of the Therapy run is massaging around eyes while running. So in my age 48 now my eyes were still normal. I would like to suggest in every learning classes school there was 2 minutes time for massaging around students eyes by themself every day.
    Good luck.

  • Dave G

    @ Red the Fister

    No need to be rude, Red. Jay is dead right … any study of environmental causative factors in any field of physiology has to include diet – even if only to filter it out of the other data. It is you , Red, who is confused between hypothesis and theory. Go read your Grade 8 Science text book.

  • Four-Eyes

    Even more mysterious is why spectacles are so expensive considering how simple the technology involved is and the kind of materials used!

  • floodmouse

    Everything I was taught really IS wrong! I was a bookworm and I was one of the only kids with glasses, and my parents insisted reading had nothing to do with bad eyesight, it was all genetics. This study only proves correlation, not causation, but I’ll bet a cause-and-effect relationship does turn up after further study. Environment and lifestyle choices turn out to affect almost every physical attribute. Most of the time, blaming your body on genetics is just a cop-out.

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