# Myopia Control Methods > Myopia control methods for Optometry: outdoor time, low-dose atropine, defocus lenses, ortho-k and evidence-based management of progressing myopia. - Canonical URL: https://prepelephant.com/topics/allied/optometry/myopia-control-methods - Exam / course: Allied Health · Subject: Optometry - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Myopia Control Methods", PrepElephant, https://prepelephant.com/topics/allied/optometry/myopia-control-methods ## Direct answer Myopia control exists because axial elongation, not blur alone, drives the lifetime risks of myopic maculopathy, retinal detachment and glaucoma — and each dioptre of myopia prevented is estimated to cut myopic maculopathy risk by roughly 40 per cent. The evidence-based toolkit has four arms: behavioural (outdoor light of at least about two hours daily, which slows onset), pharmacological (low-dose atropine — 0.01 per cent from ATOM2, with 0.05 per cent from the LAMP trial showing stronger effect), optical (orthokeratology slowing axial growth by roughly 30-60 per cent; myopia-control spectacle designs slowing progression by about half to two-thirds in trials), and correction discipline (never under-correct). Management is risk-stratified — early onset under 8-10 years, parental myopia, progression over 0.50-0.75 D per year — and monitored with cycloplegic refraction and axial length every six months. ## What you must remember - **Why control:** every dioptre avoided is associated with roughly 40 per cent lower myopic maculopathy risk; high myopia (beyond −5.00 to −6.00 D) carries the sight-threatening complications — macular degeneration, retinal detachment, glaucoma. - **Outdoor prescription:** at least about two hours of daily outdoor light delays onset; indoor lighting does not substitute, and the effect is on incidence more than progression. - **Atropine arm:** 0.01% established by ATOM2 (roughly half of untreated progression, minimal side effects); LAMP found 0.05% superior among low doses; rebound follows high-dose cessation, much less at low doses. - **Optical arm:** orthokeratology — about 30-60% axial slowing; defocus multiple-segment (DIMS) and highly aspherical lenslet (HAL) spectacles — roughly 50-67% slowing over two years; standard bifocals and progressives give only modest (roughly 10-20%) benefit. - **Under-correction is harmful:** deliberately weaker minus lenses accelerate progression in controlled studies — the old shop practice is refuted. - **Risk stratification for treatment:** onset under about 8-10 years, two myopic parents, progression beyond roughly 0.75 D per year, or childhood myopia beyond about −3.00 D — treat actively rather than observe. - **Monitoring protocol:** cycloplegic refraction plus axial length (biometry) every six months; axial elongation is the treatment target, since refraction alone is flattered by ortho-K's corneal flattening. - **Indian context:** urban school myopia is rising steeply; outdoor time and low-dose atropine remain the most affordable public-health levers across the cost gradient of DIMS/HAL spectacles and ortho-K. ## Managing a nine-year-old at risk A nine-year-old presents at −2.50 D both eyes, both parents myopic, progression −0.75 D in the past year. Baseline: cycloplegic refraction, axial length (24.4 mm), topography, and a lifestyle audit — six school hours, three coaching hours indoors, 30 minutes outdoors. The plan stacks interventions: two hours of outdoor light daily, negotiated with the parents as homework; low-dose atropine 0.05% nightly (0.01% where the stronger dilution is unavailable) with a transparent discussion of light sensitivity and near blur; and myopia-control spectacles — DIMS or HAL design — in full correction, with ortho-K offered where the family can commit to follow-up and hygiene. Six months later: axial growth 0.08 mm against an expected 0.20-0.25, refraction stable to −0.25 D, comfortable adaptation. The review continues to late adolescence with axial length as the honest yardstick — because if the family switches to ortho-K later, the flattened cornea will mask refraction while the biometer reports the truth. The exit conversation matters too: stopping atropine carries a mild rebound risk, so taper decisions wait until progression has flattened for a year. ## Where candidates stumble Quoting one number per intervention without mechanism — outdoor light and retinal dopamine, myopic peripheral defocus signalling the sclera to slow, atropine's dose-tiered effect. Reversing the under-correction answer is the single most penalised error: weaker glasses speed myopia. Confusing control with cure: axial length never shortens meaningfully; treatment brakes elongation. Forgetting practicalities — atropine's near blur in high accommodators, ortho-K's hygiene demands, the cost gradient in Indian practice. And the viva pairing: measure what you treat — axial length, not refraction alone, especially under orthokeratology. ## Frequently asked questions ### Why does each dioptre of myopia matter? Roughly 40 per cent less myopic maculopathy risk is attributed to every dioptre avoided, alongside lower retinal detachment and glaucoma risk — the rationale for treating progression, not just blur. ### What did the LAMP trial conclude about atropine doses? That 0.05% atropine slows axial progression more than 0.025% and 0.01% over two years, all well tolerated — refining ATOM2's 0.01% foundation. ### How much does outdoor time help, and for what? At least about two hours daily delays myopia onset in children; its effect on established progression is weaker, so it pairs with, rather than replaces, atropine or defocus optics. ### Which optical options control myopia best in trials? Orthokeratology (about 30-60% axial slowing) and myopia-defocus spectacle or lens designs (roughly 50-67% progression slowing), far ahead of standard bifocals or progressives. ### Why is under-correction no longer advised? Randomised studies show under-corrected myopes progress faster than fully corrected ones — the practice is discredited and should be actively counselled against.