Short-sightedness used to be something that ran in families, was managed with glasses, and was mostly treated as a minor inconvenience. The epidemiology has changed significantly. Myopia has become substantially more common in successive generations, particularly among children who spend more time on close tasks and less time outdoors. And the clinical community now recognises that high myopia – at the end of the spectrum that was once considered just "needing stronger glasses" – carries meaningful risks to long-term vision.
For most children, myopia means glasses, good vision with correction, and no long-term complications. For a minority who develop high myopia, it means a significantly elevated risk of vision-threatening conditions later in life. The goal of myopia management is to slow progression and keep as many children as possible out of that high-myopia range.
Healthbooq (healthbooq.com/apps/healthbooq-kids) covers children's eye health and vision.
The Myopia Epidemic
Myopia rates have increased dramatically in East Asia – where 80-90% of young adults in some urban populations are now myopic – and are increasing across Europe and North America. In the UK, prevalence among school-age children is estimated at around 20-35%, up from around 10-15% in previous generations. The primary driver appears to be environmental: the same genetic populations that lived rurally a generation ago have much lower myopia rates than their urban counterparts living indoor lifestyles, pointing to environmental exposure rather than genetic change.
The most studied environmental factors are time outdoors and time spent on near tasks. Ian Morgan at the Australian National University and Kathryn Rose at the University of Technology Sydney were among the first to demonstrate in large population studies that children who spend more time outdoors have significantly lower rates of myopia onset. The mechanism involves bright outdoor light stimulating retinal dopamine release, which inhibits axial elongation of the eye (the process underlying myopia). The brightness threshold matters: outdoor light (typically 10,000-100,000 lux) is orders of magnitude brighter than indoor lighting (typically 200-500 lux).
The role of near work is more debated: it is associated with myopia, but the association is weaker than the outdoor time association and confounded by the fact that high-near-work children tend to spend less time outdoors.
Who Gets Myopia
Both parents being myopic increases a child's risk significantly: roughly 40-60% of children with two myopic parents will develop myopia, compared with around 10-20% in children with no myopic parents. But genetic predisposition explains only part of the variance, and even children without myopic parents are developing the condition at increasing rates.
Myopia typically begins between ages 6-14, with the most rapid onset period in early-to-mid primary school. It tends to progress through the teenage years and stabilises in the early 20s. The younger a child develops myopia, the higher the risk of reaching high myopia by adulthood: a child who starts at age 7 has more years of progression ahead of them than one who starts at 12.
Why High Myopia Matters
Most people understand myopia as something corrected by glasses or contact lenses, and for mild myopia (under -3 dioptres) this is largely true. High myopia (-6 dioptres or above, often written as more than -6D) is different. At high levels of myopia, the eye has elongated substantially, stretching the retina and placing increased mechanical stress on the retinal tissues. This is associated with significantly elevated risk of:
Retinal detachment: the risk is approximately 8-10 times higher in high myopia than in non-myopes.
Myopic maculopathy: thinning and damage to the macula (the central area of the retina), which can cause progressive central vision loss.
Open-angle glaucoma: risk is 2-3 times higher in high myopia.
Cataracts: developing earlier than in the general population.
These risks apply primarily at the high end of myopia. The most important preventive strategy is keeping a child's myopia from progressing to the high range in the first place.
Myopia Control Treatments
The first treatment for myopia is still glasses or contact lenses to correct vision, but the goal of myopia control is slowing the rate at which the prescription increases. Several approaches have evidence:
Atropine eye drops: Low-concentration atropine (0.01-0.05%) applied nightly has the strongest evidence base for slowing myopia progression. The LAMP study (Light Adaptation and Myopia Prevention, Donald Tse and colleagues, Hong Kong) and the ATOM studies in Singapore established that low-concentration atropine reduces axial elongation significantly with minimal side effects (minimal pupil dilation at these concentrations). Rebound effect (faster progression when the drops are stopped) is less pronounced at lower concentrations. Atropine drops are available in the UK through specialist optometrists and ophthalmologists, though they are not routinely available through the NHS for myopia control.
Orthokeratology (ortho-k): Rigid contact lenses worn overnight that temporarily reshape the cornea, allowing clear vision without glasses during the day. Beyond the vision correction benefit, ortho-k has a myopia control effect: multiple studies show approximately 40-60% reduction in axial elongation compared with standard glasses. The mechanism is thought to involve peripheral defocus (the way ortho-k lenses alter the peripheral retinal image). They require careful fitting and regular monitoring.
Specific soft contact lenses: MiSight (CooperVision) is the first contact lens approved specifically for myopia control, designed with peripheral defocus rings. Evidence shows approximately 50% reduction in axial growth compared with standard contact lenses.
Peripheral defocus spectacle lenses: Lenses designed with a central zone for distance correction and surrounding zones with a different power (MiYOSMART, Stellest) to reduce the peripheral hyperopic defocus thought to drive axial elongation. Evidence shows around 50-60% reduction in myopia progression in clinical trials.
Outdoor time: Increasing time outdoors is the primary preventive strategy, particularly before myopia onset. The recommended minimum is 90-120 minutes per day outdoors. For children who already have myopia, there is weaker evidence that increased outdoor time reduces progression, but it is recommended alongside other interventions.
Practical Steps for Parents
Any child who is squinting to see the whiteboard, sitting closer to the television, or complaining of difficulty seeing at distance should have a sight test. NHS sight tests are free for children under 16 in the UK, and optometrists can provide glasses on the NHS where needed.
For a child who has been diagnosed with myopia, discussing myopia control options with an optometrist who is trained in this area is worthwhile, particularly if the child is young (under 10) at onset, progressing quickly (more than -1 dioptres per year), or has a family history of high myopia. Not all optometrists offer myopia control, and it is worth seeking out a practice that specialises in it.
The College of Optometrists in the UK provides an optometrist finder and guidance on myopia management.
Key Takeaways
Myopia (short-sightedness) is increasing rapidly in children across high-income countries, with current estimates suggesting around 30% of children in the UK are myopic, rising to potentially 50% by 2050 in some projections. The increase is driven primarily by environmental factors – reduced time outdoors and more near work – rather than genetics alone. Beyond the inconvenience of glasses or contact lenses, high myopia (above -6 dioptres) significantly increases the lifetime risk of serious eye complications including retinal detachment, glaucoma, and myopic maculopathy. Myopia control treatments (atropine eye drops, orthokeratology lenses, specific soft contact lenses) can slow the rate of progression and reduce the risk of high myopia.
