Why more and more children wear glasses: the myopia epidemic

If you have noticed that more and more children in your child's class wear glasses, you are not imagining it. According to World Health Organization data, myopia has become one of the leading threats to eye health in the 21st century, and children are the most affected.

The scale of the problem: the numbers speak for themselves

Global statistics from recent decades paint a worrying picture. In the year 2000, approximately 22% of the world's population was myopic. By 2020, this figure had risen to 34%. Researchers' projections for 2050 estimate that approximately 50% of the world's population will suffer from myopia.

But the statistics for children are even more striking. Among schoolchildren in East Asia, the prevalence of myopia already exceeds 80%. In Europe, the figures are somewhat lower, but the rate of increase is cause for serious concern: over the past 25 years, the incidence among European adolescents has doubled.

Source: Holden BA et al., Global Prevalence of Myopia and High Myopia, Ophthalmology, 2016

Why has the incidence of myopia increased?

Scientists identify several key factors that act in combination:

1. A sharp increase in close-up visual work

Modern children spend considerably more time reading, writing, and looking at screens than previous generations. Prolonged focusing at close range overloads the eye's accommodation system and stimulates elongation of the eyeball -- the primary mechanism of myopia development.

2. Lack of time outdoors

This is perhaps the best documented factor. Numerous studies have shown that children who spend less than 2 hours a day outdoors have a significantly higher risk of developing myopia. Exposure to bright daylight stimulates the production of dopamine in the retina, which inhibits eye growth.

Increasing time spent outdoors to 2 hours per day can reduce the risk of myopia development in children by nearly half -- regardless of the amount of close-up visual work.

Source: He M et al., Effect of Time Spent Outdoors at School on the Development of Myopia, JAMA, 2015

3. Genetic predisposition

If both parents are myopic, the child's risk of myopia increases 6-fold compared to children whose parents have no vision problems. However, genetics explains only part of the picture: the rapid increase in incidence over 2-3 generations cannot be explained by heredity alone.

4. Urbanization and lifestyle

Children in cities develop myopia significantly more often than those in rural areas. This is related to a combination of factors: less time outdoors, heavier academic workload, more limited visual space (walls instead of horizons), and more intensive use of electronic devices.

The COVID-19 pandemic worsened the problem

The forced shift to remote learning in 2020-2021 was a heavy blow to children's vision. Research from China showed that the prevalence of myopia among children aged 6-8 increased 1.5-3 times compared to pre-pandemic levels.

The reasons are obvious: hours of studying in front of screens, minimal outdoor time, and an almost complete absence of outdoor sports. Although restrictions were lifted long ago, the habits formed during quarantine often persist.

Source: Wang J et al., Progression of Myopia in School-Aged Children After COVID-19 Home Confinement, JAMA Ophthalmology, 2021

Why early-onset myopia is dangerous

The main problem is not that a child needs glasses. Myopia that begins early tends to progress rapidly. On average, without control, a child's myopia increases by 0.5-1.0 diopters per year. By the end of school, this can lead to high myopia (more than -6 diopters), which carries serious risks:

• Retinal detachment -- the risk increases 5-6 times
• Glaucoma -- 3 times more common than in people with normal vision
• Early cataracts -- the probability increases 3 times
• Myopic maculopathy -- irreversible damage to the central area of the retina

That is precisely why ophthalmologists worldwide speak not only about correction but about myopia control -- slowing its progression. Every diopter "saved" means a reduction in the risks of complications in adulthood.

What parents can do

The good news is that the development of myopia can be influenced. Here are the main recommendations supported by scientific research:

• Ensure 2 hours outdoors daily -- this is the most effective preventive measure
• The 20-20-20 rule -- every 20 minutes of close-up visual work, look at an object 20 feet (6 meters) away for 20 seconds
• Limit screen time -- no more than 2 hours of recreational screen time per day for schoolchildren
• Reading distance -- at least 30 cm from eyes to book or notebook
• Good lighting -- the study area should be illuminated with at least 500 lux
• Regular eye exams -- every 6-12 months with an ophthalmologist, especially if there are myopic family members

If your child has already been diagnosed with myopia, discuss modern control methods with the doctor -- special spectacle lenses, orthokeratology or soft contact lenses, low-dose atropine therapy. These methods can slow progression by 40-67%.