Patient Guide

Amblyopia (Lazy eye)

What is lazy eye?

Lazy eye is diagnosed when the sight is still poor after any refractive error has been corrected with spectacles and there is no other problem in the eye.

The brain needs stimulation of sharp pictures from the eyes to develop fully during childhood. Anything that causes blurred images in the eye will result in the respective part of the brain used for seeing to remain undeveloped. This eye will not see well because to see clearly, one needs an eye that can form sharp pictures as well as a developed portion of the brain that is able to read these pictures. Even if the eye’s condition is fully corrected later in life, vision will not recover because the brain only develops in early childhood.

What conditions cause lazy eye?

The most common causes are:

  • Squints
  • High degrees of near-sightedness, astigmatism and far-sightedness
  • Large differences in degrees between both eyes
  • Cataracts and droopy eyelids are rare causes

Does my child have a lazy eye?

Lazy eye is usually unnoticed by parents if only one eye is affected as the child will appear to have good eyesight. The only way to detect lazy eye early is to have a sight test as early as possible.

Why is early treatment important?

Lazy eye can only be successfully treated in younger children. In lazy eye, a part of the brain is underdeveloped. This can be reversed with treatment, but as the child ages, the brain gradually loses its ability to grow and respond to treatment. Therefore lazy eye should be detected and treated as early as possible. All young children should undergo regular eye tests.

Treatment of lazy eye

The condition that caused the lazy eye must be treated. This means spectacles for refractive errors, and surgery for cataracts, drooping eyelids and squints. The lazy eye itself is most effectively treated by occlusion therapy (patching of the good eye). This forces the child to use the weak eye. The patch can be held on the eye using a disposable adhesive patch or with an elastic band. Alternatively, the spectacles can be covered with opaque tape or made with frosted plastic. The more complete the blockage of light from the eye, the more effective the treatment.

Patching can be enforced full-time during all waking hours in more severe cases of lazy eye or only part of the time so that the child does not have to wear the patch to school in milder cases. Patching can cause lazy eye in the good eye but this is almost always reversible. Because of this possibility, patching should always be done under the supervision of an eye specialist. Patching may be needed from a few months to several years as the lazy eye may return if patching is stopped. Patching is usually not effective after the age of 10.

The main difficulty with patching is that no child likes to have his good eye patched. Parents must closely supervise and enforce the continuous wearing of patches and spectacles and use all means to persuade the child to cooperate.


Lazy eye is a common condition developing in childhood that often goes unrecognised. Early detection is important as it can only be treated in early childhood. All children should have regular eye tests from birth to detect lazy eye. Treatment is effective but depends on the parent’s ability to ensure that the spectacles and patches are worn constantly. The patch is always worn on the good eye.

Contact consultant 6357 2270

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