Amblyopia is a condition that results when one eye cannot see as well as it should, even with glasses or contact lenses. The good news is that amblyopia can often be successfully treated if it is diagnosed early in life.
To make sure amblyopia and other vision disorders are diagnosed early in life, the American Optometric Association encourages all parents to have their babies’ eyes checked at around six months of age.
Amblyopia begins at a very young age. Sometimes a child with amblyopia may appear to have crossed eyes or one “lazy” eye. But in most cases, the condition is very difficult for parents and other caregivers to detect.
Amblyopia develops when the nerves that connect the eye to the brain are not properly stimulated. This can happen because of physical problems in the eye that cause reduced visual clarity such as congenital cataracts, or because the eyes do not track together which results in double vision.
There are three basic types of amblyopia:
• Strabismic amblyopia
Strabismus occurs when the two eyes fail to work together as a team. If one eye looks toward the nose instead of straight ahead, the child may appear cross-eyed. Strabismus can also cause the straying eye to look out, up, or down.
This misalignment sends a blurred, double image to the brain which causes the brain to ignore the signal from the straying eye. This type of amblyopia is the cause of the common nickname “lazy eye”.
• Refractive amblyopia
A refractive error is something that keeps the eye from focusing correctly. When the vision in one eye is very blurry, either up close or at a distance, the brain may ignore that eye in favor of the clearer image from the other eye. Over time, the blurry eye weakens as the optic nerve remains unstimulated.
• Deprivation amblyopia
When something such as a congenital cataract consistently blocks light from entering the eye, that eye is not able to see clearly. Early treatment of congenital cataracts is critical for baby’s normal vision development.
Treatment for amblyopia varies depending on the cause.