When should a child's eyes be checked?

The quietness of amblyopia is what makes it slip through. A child who sees well with one eye runs, reads and draws without complaint. There is no other visual experience to compare against, so their own sight seems normal to them.

Early detection therefore rests on a schedule, not on symptoms. The checkpoints below vary between countries, so ask your doctor about the programme your child is on. The logic behind them is the same everywhere.

The brain leans on whichever eye gives it the more useful picture. If one is blurred, the other fills the gap and nothing in daily life visibly breaks down.

Parents sometimes notice by covering one eye at a time: covering the weaker eye draws no reaction, covering the good one brings an immediate protest. That is a rough observation you can make at home, not a substitute for an examination.

In the newborn period the doctor uses the red reflex test to look for anything blocking the image. Conditions such as congenital cataract are caught here.

During infancy, in most programmes between six and twelve months, there is an assessment of whether the eyes move together and whether the baby follows light and faces.

Around age three comes an important threshold. A child can now take part in an acuity measurement using pictures or symbols, and this is most often the age at which amblyopia is first caught as a number.

The pre-school check, at five to six, is the second key point: still a favourable window for treatment, and the last chance before reading and writing begin.

Through the school years, checks continue at intervals. Vision changes as a child grows, so one normal result is not a verdict that holds for life.

Some findings justify breaking the schedule. Chief among them is an eye that turns, constantly or intermittently, in a baby older than about four months.

A head held persistently tilted or turned, one eye screwed shut in sunlight, a book or screen held very close, or rapid fatigue during near work are all reasons enough to book a visit.

A pupil that looks white rather than red in photographs needs prompt assessment. The cause is often harmless, but serious conditions can present exactly this way.

If there is a family history of amblyopia, strabismus, a high prescription or childhood cataract, checks are scheduled earlier and more often even when the child shows nothing. Premature birth carries the same weight.

A school vision screening or a photoscreener is built to flag children at risk, not to diagnose them. Its output is a direction, not an answer.

So a flag raised at screening is confirmed by a full examination with drops. The reverse matters too: if the screening came back normal but what you are seeing at home continues, that observation deserves to be taken seriously.

The visual system passes through the period when it is most open to change during childhood. Amblyopia caught early usually resolves faster and with less effort, and the children whose treatment is glasses alone mostly come from this group.

That does not mean the door closes afterwards. Gains have been reported in older children and in adults too. But the easiest window in terms of options and duration is the early one, and that is the real argument for following the schedule.