Why is Nearsightedness So Common in East Asian Kids?

If you grew up East Asian, there’s a decent chance you remember a classroom full of kids wearing glasses, or eventually becoming one of them.

Turns out, there’s some real epidemiology behind that observation.

Myopia, better known as nearsightedness, has become extremely common in parts of East and Southeast Asia. Studies estimate that 80% to 90% of students leaving secondary school in some East Asian cities are myopic, with as many as 10% to 20% developing high myopia. (PMC)

Myopia happens when the eye grows too long, causing light to focus in front of the retina instead of directly on it. The result is familiar: nearby objects look clear, while things in the distance become blurry.

But myopia is more than just needing stronger glasses.

Higher levels of myopia are associated with an increased lifetime risk of serious eye conditions including retinal detachment, glaucoma, cataracts, and myopic macular degeneration, which can lead to irreversible vision loss. (PMC)

So why is it so common among East Asian children?

Genetics appear to play a role. Children with nearsighted parents are more likely to develop myopia themselves, but genes alone can’t explain how quickly rates have risen over the past several decades.

Researchers increasingly point toward a combination of intensive near work, education, urban environments, and less time spent outdoors. The rapid rise of myopia alongside changing lifestyles in East Asia has happened far too quickly to be explained by genetics alone. (PMC)

And yes, screen time may be part of the picture.

A 2025 analysis of 45 studies involving more than 335,000 people found that each additional hour of daily digital screen time was associated with 21% higher odds of myopia, with the association rising most sharply between one and four hours per day. However, because most of the underlying research was observational, the study cannot prove that screens themselves directly cause myopia. (JAMA Network Open)

One of the strongest preventive factors researchers have identified is surprisingly simple: going outside.

In a randomized trial involving nearly 2,000 first-graders in Guangzhou, China, schools added an extra 40 minutes of outdoor activity each day. After three years, 30.4% of children in the outdoor-activity group had developed myopia compared with 39.5% in the control group. (JAMA)

A 2024 Cochrane review similarly concluded that increasing outdoor time may help prevent children from becoming myopic, although the evidence is less certain about whether it slows progression once a child is already nearsighted. (Cochrane)

The International Myopia Institute currently recommends that children spend at least two hours outdoors each day to help delay the onset of myopia. Taking breaks from prolonged reading and screen use and avoiding extremely close reading distances may also help. (International Myopia Institute)

And for children whose prescriptions are already getting stronger, glasses aren’t necessarily the end of the conversation. Eye doctors now have several approaches designed specifically to slow childhood myopia progression, making regular eye exams especially important for children at higher risk.

Nearsightedness may be incredibly common in East Asian communities, but that doesn’t mean it should simply be accepted as inevitable.

For parents, something as simple as making more outdoor time part of a child’s daily routine may be one of the easiest ways to support their eye health for years to come.