Nearsightedness in American children has nearly doubled since the 1970s. In 1971, approximately 25 percent of the U.S. population between ages 12 and 54 was myopic. By 2026, that figure has risen to more than 40 percent. An estimated 9.2 million children between ages 3 and 19 in the United States have myopia.
Most parents who hear this statistic attribute it to screens. That is understandable — screens are the most visible new variable in children's daily lives over the past two decades. But researchers say the causal picture is more nuanced — and that the implication for what parents should actually do is importantly different from simply limiting screen time.
Why This Matters
Myopia is not just an inconvenience requiring glasses. High myopia — a prescription of -6 diopters or worse — significantly increases the lifetime risk of glaucoma, cataracts, macular degeneration, and retinal detachment. Children who develop myopia early (before age 10) are most likely to progress to high myopia. Preventing or delaying the onset of myopia — or slowing its progression — has real long-term consequences for vision health.
And childhood myopia has long-lasting economic consequences as well. The direct costs of myopia correction in the United States — glasses, contact lenses, refractive surgery — exceed $14.7 billion annually. Globally, the World Health Organization projects that 50 percent of the world's population will be myopic by 2050.
The Science: Why Screens Are Only Part of the Picture
Genes have not changed enough in 50 years to account for the doubling of myopia prevalence. Researchers at Oregon Health and Science University's Casey Eye Institute put it directly: "Something in the environment is driving the current uptick in myopia."
The leading environmental candidate is indoor time — and specifically, the absence of outdoor light. The mechanism is biological: natural outdoor light is much brighter than any indoor lighting, even near a window, and daylight stimulates the release of retinal dopamine in the developing eye. Dopamine signals the eye to stop elongating axially — and axial elongation is what causes myopia. When a child spends most of the day indoors, that dopamine signal is reduced, and the eye continues to elongate, causing progressive nearsightedness.
Screens, by this model, are not the primary problem — they are a proxy for indoor time. A child spending hours outdoors and several hours on a screen is significantly less myopic than a child spending most of the day indoors with similar or lower screen exposure.
A February 2026 SUNY College of Optometry study further reinforced this finding, and the broader research consensus — summarized in analyses from OHSU, CooperVision, and SPIE's photonics publications — consistently identifies time outdoors as the most effective single intervention for children not yet myopic.
Outdoor time of at least 76 minutes per day is associated with significant protective effect. Studies in Taiwan, which has the world's highest myopia rates, have found that adding two hours of structured outdoor time per school day significantly reduced new myopia onset rates in school-age children.
What This Means for Parents
The practical implication is direct: restricting screens without increasing outdoor time is a less effective intervention than increasing outdoor time regardless of screen behavior.
This does not mean screens have no effect on myopic progression. Near-work — sustained focusing at short distances — does contribute to eye elongation. And screens do most of their visual harm by displacing outdoor time, not by the screens themselves. But the lever with the strongest evidence is outdoor light exposure, not screen restriction.
The key point: if parents are going to prioritize one behavioral change, outdoor time is more strongly supported by the evidence than screen restriction alone.
What the Evidence Shows — and What It Does Not
The evidence that outdoor time is protective against myopia onset is strong and consistent across dozens of randomized trials and cohort studies across multiple countries. The evidence that screen restriction alone (without compensatory outdoor time) prevents myopia is much weaker.
What remains less certain is the precise minimum dose of outdoor time needed, and whether the protective effect is primarily from bright light or from the visual behavior of looking at distant objects in outdoor environments. Most researchers believe both factors contribute.
Treatment Options if Myopia Has Already Developed
For children who are already myopic, several interventions have evidence for slowing progression:
- Orthokeratology (Ortho-K) : Specialty contact lenses worn at night that temporarily reshape the cornea. Associated with 36–56 percent reduction in myopia progression in clinical studies.
- MiSight 1-day contact lenses : FDA-approved soft contact lenses with a special optical design that slows axial elongation. Associated with approximately 59 percent reduction in myopia progression in a 6-year trial.
- Low-dose atropine eyedrops (0.05% concentration) : The lower doses have shown effectiveness in slowing progression, unlike the 0.01% concentration that a 2023 randomized trial found to be no better than placebo.
All of these options require an eye care prescription and monitoring.
What You Can Do Now
- Prioritize outdoor time for your children — especially during summer, when the opportunity is greatest. Aim for at least 60 to 90 minutes of outdoor time per day in natural daylight.
- Schedule annual eye exams for school-age children. Myopia is frequently not detected until a child begins complaining about difficulty seeing the board at school — by which point progression may already be underway.
- If your child has already been diagnosed with myopia, ask their optometrist or ophthalmologist about myopia control options (Ortho-K, MiSight, or atropine).
- Do not focus exclusively on screen time reduction without also increasing outdoor time — the evidence suggests the latter has a stronger effect on myopia prevention.
Cost and Access: What Patients Should Know
Annual pediatric eye exams are covered by many insurance plans. MiSight contact lenses and Ortho-K require specialty fittings and are not always covered by standard vision insurance, but many optometric practices offer payment plans. Low-dose atropine eyedrops are prepared by compounding pharmacies and the cost is typically $30 to $60 per month, depending on the compounding pharmacy.
What Happens Next
The American Academy of Ophthalmology and the American Optometric Association are continuing to update guidance on childhood myopia management as new research accumulates. Multiple large trials of outdoor time interventions in school settings are underway globally, with results expected in 2027 and 2028.
The Bottom Line
Childhood myopia has nearly doubled in the United States since the 1970s. Screens are a contributing factor — but primarily because they displace outdoor time. The research is clear that increasing outdoor time in natural daylight is the most effective single intervention for reducing myopia onset in children, more effective than screen restriction alone. This summer, outdoor time is not just good for kids' mental and physical health — it may also protect their eyesight.
