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Lens and refraction · Z
Children’s vision milestones
A guide, not a score
Last reviewed: 2026-10-06 · 潘家健醫生
Key points
Child vision milestones are rough guides with wide variation — not a test score substitute.
A persistent turn after about 3–4 months needs prompt specialist assessment — usually not same-day emergency, but do not wait until school.
A white pupil at any age: A&E now or same-day dilated exam.
Children often need cycloplegic refraction; without it hyperopia can be underestimated.
Rough public-education timing only. Babies start regarding faces in the first weeks. Alignment should settle around 2–3 months. Persistent squint after 3–4 months: see an ophthalmologist promptly. Usually not a same-day emergency, but do not wait until school. A white pupil (leukocoria) at any age: go to A&E now, or same-day dilated exam by an ophthalmologist to exclude retinoblastoma and other causes. Do not wait and watch at home. New nystagmus that is asymmetric, or with diplopia, severe vertigo or neurological signs: A&E / 999; new nystagmus without those red flags: same-day ophthalmic assessment. Known stable, long-standing congenital or infantile nystagmus alone is not automatic “go to A&E now”. Preschool is an important window for amblyopia, strabismus and high refractive error.
This is general medical information, not a diagnosis, and cannot replace an in-person consultation with a registered ophthalmologist, refraction, or a dilated fundus exam. It is not advice to use any medicine or undergo any procedure. Medicines (including off-label use), laser or surgery must be decided by a registered doctor after examination, according to indications and Hong Kong registration. Figures from the literature are published averages, not any clinic’s results. This site does not book, prescribe or refer. Do not change treatment on your own.
