Paediatric Vision

Amblyopia is reduced vision in one eye (occasionally both) caused by abnormal visual development in childhood — the brain suppresses the image from the weaker eye to avoid double vision or blur. It is not a structural problem with the eye itself (the eye is usually physically normal) but a developmental wiring problem in the visual cortex. Causes: unequal refractive error between the two eyes (anisometropia), squint (the brain suppresses the turned eye), or anything blocking vision in early childhood (cataract, droopy eyelid). Treatment: correct the underlying cause (glasses, cataract surgery), then force the weaker eye to work by patching the stronger eye for several hours daily. The critical window is before age 7-8; treatment is most effective under 5. Late-detected amblyopia in adults has limited treatment response, underscoring why early screening matters.

A squint (strabismus) is a misalignment of the eyes — one or both eyes turn in (esotropia), out (exotropia), up, or down. Obvious squints are noticed by parents; subtle squints can be missed. Signs to watch for: one eye that appears to wander or point in a different direction, tilting or turning the head to see clearly, closing one eye in bright sunlight, or a 'white reflex' in photos where one eye looks white instead of the normal red-eye. All babies have intermittent eye wandering in the first 2-3 months — this is normal. A persistent squint beyond 3-4 months of age, or any squint in an older child, needs prompt paediatric ophthalmology evaluation. Don't accept 'he'll grow out of it' — squints don't resolve on their own and cause amblyopia if untreated.

Red reflex test at birth (done by paediatrician or neonatologist) — screens for congenital cataract and serious eye pathology. Screening at 3-4 years — amblyopia, squint, and significant refractive error detection; even children who cannot read a chart can be tested with picture charts and objective refraction. School-entry screening (age 5-6) — vision chart assessment catches most significant refractive errors. Annual check thereafter if risk factors exist: a parent or sibling with high myopia, known squint or amblyopia, premature birth (retinopathy of prematurity), or systemic conditions that affect eyes (diabetes, certain syndromes). Signs that should trigger immediate evaluation at any age: asymmetric red reflex, any squint, white pupil, persistent watering, unusual eye movements, or a child who is clearly struggling to see.

No — glasses don't weaken eyes and this is a common and harmful misconception. Glasses correct the refractive error so the child sees clearly; not wearing them when needed allows amblyopia to develop or worsen, and causes unnecessary visual deprivation during a critical developmental window. Children with significant hyperopia (long-sightedness) need glasses to see clearly up close and to prevent the accommodative effort from causing a convergent squint. Children with myopia need glasses for distance — not wearing them doesn't slow myopia progression (evidence shows it may accelerate it, as the blur signal may drive the eye to elongate further). Glasses prescribed by a properly qualified optometrist or ophthalmologist after a careful refraction are appropriate and necessary — not overtreatment.

Colour blindness (colour vision deficiency) is usually inherited (X-linked, affecting approximately 8% of males and 0.5% of females) and involves absent or abnormal cone photoreceptors — most commonly affecting red-green discrimination. There is currently no treatment that corrects the underlying cone deficiency. Special tinted contact lenses and glasses (EnChroma lenses) can enhance colour contrast for some people with red-green deficiency, improving colour discrimination in certain situations, though they don't restore normal colour vision and effects vary. Acquired colour blindness (from optic nerve disease, macular degeneration, or medications) is a separate issue — treated by addressing the underlying condition. The practical focus for children is awareness: informing teachers about colour vision deficiency so tasks requiring colour identification are adapted, and steering career guidance (certain professions — air traffic control, some armed forces roles, electrical wiring — require normal colour vision).