Prevention & Early Habits
How To Prevent Myopia
Myopia isn't entirely preventable, but strong evidence shows the right daily habits, and for at-risk children, active treatment, can genuinely lower the risk or delay onset.
Myopia isn't entirely preventable, but strong evidence shows the right daily habits, and for at-risk children, active treatment, can genuinely lower the risk or delay onset.
Genetics plays a real role in myopia, and no daily habit can override a strong family history entirely. But the sharp rise in myopia over the last few decades has happened far too quickly to be explained by genetics alone, which means environment and daily habits genuinely move the odds, sometimes considerably.
The clearest, best-evidenced lever we have is time spent outdoors during childhood. For children already showing early warning signs, there's also a growing, genuinely evidence-based case for active treatment before myopia even begins. This page covers both. If myopia has already started, our Myopia Control page covers the treatments used to slow it from progressing further.
Across numerous studies, children who spend more time outdoors consistently show lower rates of myopia onset. Around two hours a day is the most commonly cited protective target, and some research suggests each additional hour outdoors per week further reduces risk, meaning more genuinely seems to help.
The likely explanation is light. Outdoor light levels, even on an overcast day, are dramatically brighter than almost any indoor environment, roughly 10,000 to 18,000 lux outdoors compared with 100 to 150 lux indoors. That brighter light appears to boost retinal dopamine release, which is thought to slow the type of eye elongation associated with myopia. Relaxed, distance-focused outdoor viewing, quite different from indoor near work, likely contributes too.
Myopia doesn't appear out of nowhere. In most children, two measurable changes happen first, often a year or more before any blur shows up.
Most young children start out with a small amount of natural long-sightedness, their “hyperopic reserve,” which is gradually used up as the eye grows. A child with less reserve than expected for their age, or one losing it unusually quickly, for example around half a dioptre or more in a year, is showing one of the earliest signs that myopia may follow.
The more telling sign is axial length itself. Longitudinal research tracking children through the onset of myopia has found that eye growth speeds up sharply in the year immediately before myopia begins, with future myopes growing roughly three times faster than children who stay non-myopic, before settling to a steadier rate of progression once myopia is established.
Because axial length changes the most right before myopia appears, a single measurement taken after myopia is already diagnosed tells us less than a series of measurements taken beforehand. This is exactly why we measure axial length on every child seen for the first time at our clinic, whether or not they currently need glasses. It gives us a genuine baseline to compare against, so acceleration can be caught early rather than inferred after the fact.
For children showing clear warning signs, a rapidly depleting hyperopic reserve or accelerating axial length, we sometimes recommend active treatment before myopia has technically even begun. The goal is to delay onset for as long as possible, since later onset generally means less total myopia by the time growth finishes.
Nightly eye drops, at a low concentration determined individually by our optometrist, used off-label in select at-risk children to help delay the onset of myopia rather than only slow it once established. Trial evidence in pre-myopic children has shown fewer children going on to develop myopia, and less myopic shift overall, compared with no treatment.
Everyday spectacle lenses built with the same peripheral defocus technology used in myopia control, but fitted in plano (no distance power) or a low plus power, for children who aren't myopic yet but show a depleting hyperopic reserve. We use Stellest 2.0 for children ready for a plano preventive lens, and MiyoSMART iQ, now also available in plus powers, for children who still have some hyperopic reserve to correct while adding this protective effect.
Active pre-myopia intervention is a genuine option, not a default recommendation. It's reserved for children whose risk profile and measured trends, family history, hyperopic reserve, and axial length trajectory together, suggest myopia is genuinely likely soon. We discuss this openly at your child's assessment rather than assuming it's needed.
None of these guarantee myopia won't develop, but each addresses a factor the evidence consistently links to risk.
Aim for around two hours a day where practical. It doesn't need to be structured activity, ordinary outdoor play, sport or simply walking to school all count.
Encourage holding books and devices at a normal arm's length rather than very close, since sustained close-range focusing at short distances is linked to higher risk.
The 20-20-20 rule, a 20-second look at something roughly 6 metres away every 20 minutes, is a simple way to interrupt long stretches of sustained close focusing.
Even with good habits, some children will still develop myopia. We measure axial length at every child's first visit, whatever their age or prescription, so we have a genuine baseline to track against rather than only starting to measure once myopia is already diagnosed.
If myopia does develop despite good habits, that's not a failure, genetics is often the bigger factor at that point. Outdoor time and sensible near work habits remain worthwhile even then, but slowing further progression becomes primarily the job of purpose-built myopia control treatment, not lifestyle changes alone.
Whether or not myopia has started, a comprehensive eye test, including a genuine axial length baseline, gives you a clear picture and practical, personalised advice for your child.