How to Care for and Control Myopia in Children: Research-Backed Tips for Healthy Eyes
Myopia (short-sightedness) in children is rising worldwide. Researchers estimate that by 2050 almost half the world's population will be myopic, and around 1 billion people will have high myopia (Holden et al., 2016).
The good news is that parents can lower the risk and slow myopia down. In this article, GALAXY BY OPTOMETRIST explains the research-backed methods in plain language.
30-second summary ✔ Let your child spend about 2 hours a day outdoors (shade works too) ✔ Rest the eyes with the 20-20-20 rule and keep books or screens more than 30 cm away ✔ Wear the correct prescription, have eyes checked every 6 months and consider myopia control lenses
What causes myopia in children?
Myopia means distant objects look blurry while near objects stay clear. The main cause is an eyeball that is longer than normal, so light focuses in front of the retina instead of on it.
Children's eyes keep growing longer as they grow. The earlier myopia starts, the more it tends to increase. Key risk factors are:
A parent who is myopic
Long, continuous close-up work, holding books or screens too close
Too little time outdoors
High myopia is not just about thick glasses. It raises the risk of eye disease later in life, such as retinal detachment, myopic maculopathy and glaucoma, which is why slowing myopia in childhood matters.
1. Get your child outdoors for about 2 hours a day
This is one of the best-proven ways to prevent myopia.
Earl L. Smith III (University of Houston) induced myopia in rhesus monkeys and found that under normal lighting 89% (16 of 18) became myopic, but with extra light of about 25,000 lux for 6 hours a day only 25% (2 of 8) did. This supports the idea that bright outdoor light is a key protective factor (Smith et al., 2012).
A school trial in Guangzhou, China added one 40-minute outdoor class per school day for 3 years. New myopia developed in 30.4% of these children versus 39.5% in the control group (He et al., 2015).
A trial in Taiwan encouraged children to go outside at recess, adding up to about 11 hours a week. The risk of rapid myopia progression fell by 54%, and shade under trees or verandas (≥1,000 lux) also worked, with no need for harsh sun (Wu et al., 2018).
The Sydney Myopia Study found that what matters is time spent outdoors, not sport itself, as indoor sport did not help (Rose et al., 2008).
Good to know A meta-analysis found that outdoor time clearly helps prevent myopia from starting, but its effect on slowing myopia in children who are already myopic is unclear (Xiong et al., 2017). Children who are already myopic should also use a myopia control method.
In everyday life: walks, cycling, playgrounds and activities under the trees. Wear a wide-brimmed hat or sunglasses when the sun is strong.
2. The 20-20-20 rule and the 30 cm distance
The 20-20-20 rule: every 20 minutes, look at something 20 feet (about 6 metres) away for 20 seconds.
The rule was created by American optometrist Dr. Jeffrey Anshel in the early 1990s to relieve digital eye strain. A 2022 study found that reminders to follow it reduced eye strain and dry eye symptoms within 2 weeks, but the symptoms returned once people stopped (Talens-Estarelles et al., 2022), so it needs to become a habit.
For myopia itself, a study of more than 10,000 children in Taiwan found these habits were linked to less myopia (Huang et al., 2020):
Holding books or screens more than 30 cm away (the strongest protective effect)
Taking a break every 30 minutes
Going outside to play at recess
3. Limit screen time by age
Under 2: screen time is not recommended
Ages 2–4: no more than 1 hour a day (WHO, 2019)
Older children: set family rules, such as no screens at meals or before bed, and more time outdoors than on screens
Make sure the study desk is well lit, sit upright, and avoid reading or using screens in the dark.
4. Have regular eye exams
All children: at least once a year, especially before starting school
Children who are already myopic: every 6 months to track prescription and eye length
Signs it's time for an eye exam: squinting at distant objects, sitting close to the TV, leaning close to books, frequent eye rubbing, or a teacher reporting trouble seeing the board.
5. Wear the right prescription, and choose lenses that slow myopia
Regular single-vision glasses help your child see clearly but do not slow myopia. Glasses should never be made weaker than the true prescription in the hope of stopping myopia from increasing.
To slow myopia, these research-backed options are available:
Myopia control spectacle lenses such as HOYA MiYOSMART have a clear central zone surrounded by many tiny lenslets that focus light in front of the retina, signalling the eye to grow more slowly. The concept builds on Earl Smith's research showing that the peripheral retina influences eye growth (Smith et al., 2005).
Ortho-K: rigid contact lenses worn overnight that temporarily reshape the cornea, giving clear vision during the day without glasses.
Low-dose atropine eye drops: prescribed and monitored by an ophthalmologist, and can be combined with glasses.
The right option depends on your child's age, prescription and lifestyle, so it should be assessed by an optometrist or ophthalmologist.
6. Diet and sleep: good for overall eye health
A balanced diet with leafy greens, yellow-orange fruit and vegetables, and fish supports healthy eyes, and children should get enough sleep for their age. However, there is no evidence that any food or vitamin prevents or slows myopia, so treat these as extras, not the main strategy.
4 common myths parents believe
1. "Weaker glasses, or none at all, stop eyes getting worse"
❌ Why people believe it: fear that glasses make eyes "lazy", and seeing the prescription rise every year despite wearing glasses.
✔ The fact: myopia increases because the eye grows longer, not because of glasses. A randomised study of 94 children aged 9–14 found that those given weaker-than-needed glasses progressed faster than fully corrected children over 2 years (Chung et al., 2002), and a review found no benefit from under-correction, so full correction is recommended (Logan & Wolffsohn, 2020).
2. "Blue-light glasses prevent myopia"
❌ Why people believe it: myopia has risen along with phone use, and screens emit blue light.
✔ The fact: the real issue with screens is long periods of close-up work and less time outdoors, not blue light. Blue-light lenses may help with glare but do not slow myopia; that requires dedicated myopia control lenses.
3. "Carrots, blueberries or eye vitamins prevent myopia"
❌ Why people believe it: Vitamin A is known to be good for the eyes, and eye supplements are heavily advertised.
✔ The fact: Vitamin A deficiency causes night blindness, not myopia. There is no evidence that any food or vitamin prevents or treats myopia.
4. "Eye exercises can cure myopia"
❌ Why people believe it: the belief that myopia comes from tired or weak eye muscles.
✔ The fact: myopia is caused by an eyeball that is too long, and exercises cannot make it shorter. Resting the eyes with the 20-20-20 rule (every 20 minutes, look 20 feet or 6 metres away for 20 seconds) eases eye strain and dry eye (Talens-Estarelles et al., 2022), but it does not reduce the prescription.
Checklist for parents
✔ About 2 hours outdoors a day (shade is fine) ✔ 20-20-20 during all close-up work ✔ Books and screens more than 30 cm away ✔ Age-appropriate screen limits ✔ Regular eye exams (every 6 months if already myopic) ✔ The correct prescription, and consider myopia control lenses
Talk to GALAXY BY OPTOMETRIST about your child's eyes
GALAXY BY OPTOMETRIST is an optometrist-led eye care centre offering thorough eye exams for children and advice on the myopia control lenses that suit your child best.
📍 Pantip Ngamwongwan, 2nd Floor, Central Zone, Room 2026, Ngamwongwan Rd., Bang Khen, Mueang Nonthaburi, Nonthaburi
This article is general information, not a diagnosis. Please consult an optometrist or ophthalmologist for a proper assessment.
References
Holden BA, et al. Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036-1042.
Smith EL 3rd, Hung LF, Huang J. Protective effects of high ambient lighting on the development of form-deprivation myopia in rhesus monkeys. Invest Ophthalmol Vis Sci. 2012;53(1):421-428. PubMed
Smith EL 3rd, et al. Peripheral vision can influence eye growth and refractive development in infant monkeys. Invest Ophthalmol Vis Sci. 2005;46(11):3965-3972.
He M, et al. Effect of time spent outdoors at school on the development of myopia among children in China. JAMA. 2015;314(11):1142-1148. JAMA
Wu PC, et al. Myopia prevention and outdoor light intensity in a school-based cluster randomized trial. Ophthalmology. 2018;125(8):1239-1250. PubMed
Rose KA, et al. Outdoor activity reduces the prevalence of myopia in children. Ophthalmology. 2008;115(8):1279-1285.
Xiong S, et al. Time spent in outdoor activities in relation to myopia prevention and control: a meta-analysis and systematic review. Acta Ophthalmol. 2017;95(6):551-566. PubMed
Huang PC, et al. Protective behaviours of near work and time outdoors in myopia prevalence and progression in myopic children. Br J Ophthalmol. 2020;104(7):956-961.
Talens-Estarelles C, et al. The effects of breaks on digital eye strain, dry eye and binocular vision: testing the 20-20-20 rule. Cont Lens Anterior Eye. 2023;46(2):101744.
Chung K, Mohidin N, O'Leary DJ. Undercorrection of myopia enhances rather than inhibits myopia progression. Vision Res. 2002;42(22):2555-2559. PubMed
Logan NS, Wolffsohn JS. Role of un-correction, under-correction and over-correction of myopia as a strategy for slowing myopic progression. Clin Exp Optom. 2020;103(2):133-137. PubMed
World Health Organization. Guidelines on physical activity, sedentary behaviour and sleep for children under 5 years of age. 2019.
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