About 36% of children and adolescents worldwide are nearsighted today, up from roughly 24% in 1990. Among adults globally, an estimated 2.6 billion people had myopia as of 2020. The rate varies dramatically by age, region, and decade, and it’s climbing fast enough that researchers project nearly 40% of young people will be nearsighted by 2050.
Global Rates Over Time
Nearsightedness has surged over the past few decades. A comprehensive meta-analysis published in the British Journal of Ophthalmology tracked the pooled prevalence among children and adolescents from 1990 to 2023. In 1990, roughly 24% of young people were nearsighted. By 2023, that figure had risen to about 36%. Projections put it at 40% by 2050, which would translate to over 740 million affected children and teens worldwide.
The trend is not unique to one country. The World Health Organization estimated 2.6 billion people of all ages were living with myopia in 2020, making it the most common refractive error on Earth. Two out of three people in low-income countries who need glasses still don’t have access to them, which means many of those affected are navigating daily life with uncorrected blurry distance vision.
The United States: A 66% Jump in Three Decades
In the U.S., the shift has been especially well documented. A large national survey found that 25% of Americans were nearsighted in the early 1970s. Three decades later, 42% were. That’s a 66% increase. Mild cases rose modestly, from about 13% to 18%, but moderate and higher prescriptions drove the bulk of the growth. Among Black Americans, the overall rate was lower than in white Americans but still jumped from 13% to 34% over the same period.
East Asia Has the Highest Rates
The most striking numbers come from East Asia. In China, a systematic review covering millions of children found an overall myopia rate of 36.6%, but the age breakdown tells a sharper story. Only about 3% of children under 5 were nearsighted. By ages 10 to 14, the rate hit 45%. Among 15- to 19-year-olds, 67% were nearsighted. In some urban areas of South Korea, Taiwan, and Singapore, studies have reported rates above 80% in young adults.
These numbers dwarf those in most Western countries, where young adult myopia rates typically fall between 30% and 50%. The gap is thought to reflect differences in education intensity, time spent on close-focus tasks, and hours spent outdoors during childhood.
Why Nearsightedness Happens
Nearsightedness occurs when the eyeball grows too long from front to back. Light entering the eye focuses in front of the retina instead of directly on it, making distant objects blurry while close-up vision stays sharp. The retina itself plays a key role in regulating this growth. It can detect whether incoming images are focused properly and sends chemical signals through surrounding tissue layers to speed up or slow down the elongation of the eye wall.
When those signals push the eye to keep growing longer than it should, the result is progressively worsening myopia. Genetics matter: if both parents are nearsighted, a child’s risk is significantly higher. But the rapid rise in prevalence over just a few decades points clearly to environmental factors, since genes don’t change that fast across a population.
How Severity Is Classified
Eye doctors categorize nearsightedness by how strong of a corrective lens you need, measured in diopters. The American Academy of Ophthalmology breaks it into three tiers:
- Mild (low) myopia: less than 3 diopters. You can function without glasses in many situations but struggle with road signs, movie screens, or classroom boards.
- Moderate myopia: 3 to 6 diopters. Distance vision is significantly blurred without correction.
- Severe (high) myopia: more than 6 diopters. Everything beyond arm’s length is blurry without glasses or contacts.
Most nearsighted people fall into the mild category. In China’s pediatric data, about 5.3% of children had high myopia overall, but among teenagers aged 15 to 19, nearly 1 in 10 had already crossed that threshold. High myopia isn’t just an inconvenience requiring thicker lenses. It’s a medical risk factor.
Why High Myopia Is a Health Concern
As the eyeball stretches, it puts mechanical stress on the retina, the blood vessel layer behind it, and the tough outer wall of the eye. This stretching raises the risk of several serious conditions later in life. Compared to someone with normal-length eyes, a person with mild to moderate myopia has roughly a 4-fold increased risk of retinal detachment. For those with prescriptions stronger than 3 diopters, the risk jumps to 10-fold. People with high myopia (beyond 5 diopters) face a lifetime risk of retinal detachment that is 20 times higher than average.
These aren’t just statistical curiosities. Retinal detachment can cause permanent vision loss if not treated quickly. High myopia also raises the risk of other conditions that damage vision over time, including abnormal blood vessel growth at the back of the eye and increased pressure inside the eye. This is why the rising prevalence of myopia, especially high myopia in young people, is treated as a public health issue rather than simply a matter of needing glasses.
Outdoor Time and Prevention
One of the most consistent findings in myopia research is that time spent outdoors during childhood reduces the risk of becoming nearsighted. Randomized controlled trials have shown reductions in myopia onset ranging from 11% to 52% in children who weren’t yet nearsighted. The protective effect appears to plateau at about 120 minutes of outdoor time per day.
The benefit is strongest for younger children whose eyes haven’t yet started shifting toward myopia. For kids already on the verge of developing it, the protection is weaker and less statistically reliable. Bright outdoor light is thought to be the key ingredient, not physical activity itself, because it triggers the release of compounds in the retina that help slow eye elongation.
This finding has driven policy changes in parts of East Asia. Schools in Taiwan and China have introduced mandatory outdoor recess periods specifically to combat myopia rates. The logic is straightforward: if you can slow eye growth during the critical childhood years, you reduce both the number of people who become nearsighted and the number who progress to high myopia with its associated health risks.
The Numbers at a Glance
Roughly one in three young people worldwide is nearsighted today. In the U.S., it’s closer to two in five. In parts of East Asia, it’s two in three among teenagers. These rates have roughly doubled in many populations since the 1970s and show no sign of leveling off. By 2050, projections suggest nearly 40% of children and adolescents globally will be affected, making nearsightedness one of the most common chronic conditions of the 21st century.