Lazy eye in children: a guide for parents

Why childhood matters

Lazy eye means that vision in one eye did not develop as well as it should, and glasses alone cannot fully fix it. The eye itself is often healthy. The problem lies in how the eye and brain work together [1].

The National Eye Institute says that it can be hard to notice, and that all children should have their vision checked at least once between the ages of 3 and 5 [1]. The American Academy of Ophthalmology says that children often do not realise they see poorly with one eye, and that treatment works best when it starts before about age 7 or 8 [16]. The NHS also says that treatment should ideally start before the age of 7 [15].

The US Preventive Services Task Force estimates that 1 to 6 percent of children under 6 have amblyopia or a risk factor for it [26].

What causes it

Lazy eye develops when the brain receives a clearer picture from one eye than from the other, and starts to rely on the clearer one. The main risk factors named by the Task Force are [26]:

• Strabismus, where the eyes point in different directions.
• Anisometropia, where the two eyes need very different glasses prescriptions.
• High refractive error in both eyes that has not been corrected.
• Media opacity, such as a cataract, which blocks the view into the eye.

The Task Force also lists a family history of amblyopia, premature birth and low birth weight among other risk factors [26]. Our page on what lazy eye is explains the types in more detail. The signs to watch for are covered on their own page.

Eye checks for children

Checks start very early. In the UK, a newborn eye check is done within 72 hours of birth, and another at 6 to 8 weeks. Many areas also offer vision screening at school around age 4 to 5, although this varies by area. The NHS advises seeing an optician if you are worried or if screening was not offered [27]. Eye tests are free for children under 16, and for those under 19 in full-time education [27].

In the US, the Task Force recommends vision screening at least once for all children aged 3 to 5. It found that the evidence for children under 3 was not enough to judge the balance of benefit and harm [26]. The American Academy of Pediatrics advises checking the eyes of newborns, and instrument-based screening from about 12 months to 3 years, repeated each year until the child can do a letter test. Children who fail are referred to an eye specialist for children [28].

Rules differ by country and area, so ask your doctor or optician which checks apply to your child.

How it is treated

Treatment starts by finding the cause. Glasses come first if there is a focusing problem. If vision is still uneven, the usual next step is to make the weaker eye work harder. Common options are:

• Glasses. In one study of 84 children aged 3 to under 7, glasses alone improved vision by two or more lines on the eye chart in 77 percent. In 27 percent, the amblyopia was fully resolved. It could take up to 30 weeks for vision to stop improving [29].
• Patching. A patch covers the stronger eye for some hours a day. In a trial of 189 children under 7, 2 hours and 6 hours of daily patching, plus close-up activities, gave similar results. In each group, vision improved by about 2.4 lines on average [30]. See our page on eye patching.
• Atropine drops. Drops blur the stronger eye and have a similar purpose to a patch [15].
• Dichoptic games. Some newer treatments show a different picture to each eye. Read our summary of dichoptic therapy. The evidence is still developing, so ask your eye doctor whether it suits your child.

The Pediatric Eye Disease Investigator Group has run many trials, and its results are a useful guide to what works for children [2]. Our treatment overview compares the options.

What to expect

Improvement is often gradual. The Task Force described the benefit of treatment as moderate, and noted that the gains may last through life [26]. Not every child reaches normal vision, and treatment can take months. Your eye doctor will re-check vision at follow-up visits and adjust the plan.

The eye can slip back after treatment stops, so follow-up matters. Our FAQ covers this in more detail.

Helping at home

These are general suggestions, not results from the studies above:

• Keep to the plan your eye doctor gives you, and keep appointments.
• Make treatment part of the daily routine, at the same time each day.
• Praise effort. Children do better when treatment feels like a shared task.
• Choose close-up activities your child enjoys, such as drawing or building.
• Tell your eye doctor if the treatment is upsetting your child or is hard to keep up.

ZyncView offers free dichoptic games at home as a wellness and entertainment activity. They are not a treatment and not a replacement for an eye check or for any care your child's doctor advises.

Questions to ask

• What caused the lazy eye in my child, and could it affect the other eye?
• Which treatment do you advise, for how long, and how will we measure progress?
• When is the next check, and what result are we aiming for?
• What should we do if the treatment is not being tolerated?
• Should other members of the family have their eyes checked?