I (Can’t) See: How myopia becomes a pandemic


A recent item in the Taipei Times newspaper really stands out and scares you, if you stand close enough to read it.

Ninety percent of kids in major Taiwanese cities have myopia

Thu, Aug 31, 2017

Myopia is increasingly affecting young people in Taiwan, with close to 90 percent of children in Taiwan’s major cities suffering from nearsightedness. If myopia is not controlled and a child’s vision worsens, their eyesight could be damaged, even with treatment. In these cases, it could cause complications such as degeneration, detachment or tearing of the retina, macular degeneration, cataracts and glaucoma. In serious cases surgery may be required, and the complications could even lead to impaired vision.

I have jokingly told my students in the past, both in South Korea and Taiwan, “You should spend more time in the big blue room,” then had to explain what the euphemism mean. Maybe I should be and have been more serious about it.  Emphasis mine in the snippet below:

Myopia (Nearsightedness) from the American Optometric Association

Nearsightedness, or myopia, as it is medically termed, is a vision condition in which people can see close objects clearly, but objects farther away appear blurred. People with myopia can have difficulty clearly seeing a movie or TV screen or the whiteboard in school.

Myopia occurs if the eyeball is too long or the cornea (the clear front cover of the eye) is too curved. As a result, the light entering the eye isn’t focused correctly, and distant objects look blurred.

Myopia affects nearly 30 percent of the U.S. population. While the exact cause of myopia is unknown, there is significant evidence that many people inherit myopia, or at least the tendency to develop myopia. If one or both parents are nearsighted, there is an increased chance their children will be nearsighted.

Even though the tendency to develop myopia may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop myopia.

Generally, myopia first occurs in school-age children. Because the eye continues to grow during childhood, it typically progresses until about age 20. However, myopia may also develop in adults due to visual stress or health conditions such as diabetes.

Myopia may also occur due to environmental factors or other health problems:

[…]

People who do an excessive amount of near-vision work may experience a false or “pseudo” myopia. Their blurred distance vision is caused by overuse of the eyes’ focusing mechanism. After long periods of near work, their eyes are unable to refocus to see clearly in the distance. Clear distance vision usually returns after resting the eyes. However, constant visual stress may lead to a permanent reduction in distance vision over time.

Time also published an item in 2012 saying the same things:

Why Up to 90% of Asian Schoolchildren Are Nearsighted

May 07, 2012

Scientists say an epidemic of myopia, or nearsightedness, is sweeping through Asian children, and is likely due to students’ spending too much time indoors studying and not enough time outside in the sunlight.

It has long been thought that nearsightedness is mostly a hereditary problem, but researchers led by Ian Morgan of Australian National University say the data suggest that environment has a lot more to do with it.

Reporting in the journal Lancet, the authors note that up to 90% of young adults in major East Asian countries, including China, Taiwan, Japan, Singapore and South Korea, are nearsighted. The overall rate of myopia in the U.K., by contrast, is about 20% to 30%.

Myself, my lousy parents never got me proper glasses until I was in my mid teens which meant I did a lot of squinting and sitting close to things.  It makes me wonder if it played a role in how my own vision changed.  My left was dominant as a child, then gradually equalized in my late teens.  Optometrists here haven’t told me to get bifocals, but I suspect those in Canada would.

Comments

  1. jazzlet says

    I have no idea where I saw it, but some research suggests that not just getting outside, but focusing on things at a distance can help alleviate the effects of a lot of close work. I am ucky enough to have a decent view outside my window and looking at the hill outback does feel like resting my eyes.

  2. jrkrideau says

    I don’t know it was the Lancet study or another but an Australian researcher from Sydney—cannot remember the name of the university—presented some interesting research on fairly well–matched samples from Singapore and Sydney that suggested children needed a minimum number of hour in natural light (11 hr/week perhaps?) for healthy eyes.

    No single study is conclusive but her results were enough that if I had any pre-teens littering the place I’d be tossing them outdoors regularly.

    • jrkrideau says

      Probably both but the study I mentioned above (sorry I have lost the reference) is quite convincing that behaviour—very little exposure to natural light—can lead to myopia.

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