What is amblyopia?

Amblyopia is a childhood problem that happens when one eye is weaker than the other. The brain chooses to take in images from the stronger eye and ignore images from the weaker eye. This means that your child uses the strong eye more than the weak eye. If the weak eye doesn't have to work, it isn't able to develop good vision. This leads to poor vision in the weaker eye.

Amblyopia usually affects only one eye.

The problem starts between birth and about age 7. Your child may not even know that they are using only one eye. Ignoring the images from the weak eye is an automatic response. Your child has no control over it.

Early treatment usually can reverse amblyopia. The younger your child is when treatment starts, the more likely your child is to have good vision.

Amblyopia is sometimes called "lazy eye."

What are the symptoms?

Your child may have an eye that wanders or doesn't move with the other eye. Their eyes may not fix on the same point. They might complain when one eye is covered. Some children squint or tilt their head to look at something. Or they may have an upper eyelid that droops.

How is it treated?

For amblyopia to be treated, your child must use the weak eye. This will force the eye to get stronger. Over time this corrects the vision in the weak eye.

Your doctor may suggest:

• Blocking the strong eye with an eye patch.
• Blurring the strong eye with eyedrops or glasses.

Your child may have to wear the patch or glasses most of the day or for just part of each day. Treatment may last for a few weeks or months. Severe cases may take longer.

If another problem is causing the amblyopia, such as a cataract, it also needs to be treated.

Treatment is best started before age 6 and should begin before your child's vision has fully developed, around age 9 or 10.

After treatment ends, be sure to set up follow-up eye examinations for your child. Amblyopia can return even after successful treatment.