Amblyopia (“lazy eye”)

Vision develops in the first years of life. If one eye sends the brain a blurred or misaligned image, the brain starts to favour the other eye and the weaker eye’s vision does not develop. The eye is healthy but has “not learned to see”.

THE EYES AND THE BRAIN

How a lazy eye is treated

The brain learns to use both eyes during childhood.

1

Normal vision

Both eyes send sharp images and the brain uses both.

2

Amblyopia

One eye sends a blurred image and the brain starts to ignore it.

3

Patching

Covering the good eye makes the brain use the weaker eye, and its vision improves.

What are the causes?

• A difference in prescription between the two eyes (anisometropia), the most common and least noticeable cause.
• Strabismus: a turned eye.
• A high prescription in both eyes.
• Something blocking vision, such as a drooping eyelid or a congenital cataract.

How is it treated?

• Glasses with the full prescription, worn all day. On their own, they improve many cases.
• Patching: covering the good eye with a patch for some hours a day, to make the brain use the weaker eye.
• Alternatively, atropine drops in the good eye, which blur its near vision.
• Treating the cause, for example operating on a cataract or a ptosis covering the pupil.

Treatment requires persistence from the family and regular appointments over months. After age 7 to 8 the response is smaller, although some improvement is still possible. That is why an eye examination at pre-school age is recommended, even if the child seems to see well.

This information does not replace an individual medical assessment. Follow the advice of the team looking after you.