Amblyopia (Lazy Eye)
Also known as “lazy eye,” amblyopia is poor vision in an eye that did not develop normal sight during early childhood.When one eye develops good vision while the other does not, the eye with the poorer vision is called amblyopic.It is a relatively common condition, affecting two to three percent of the population.
What causes amblyopia?
There are three major causes:
- Strabismus, misaligned or crossed eyes, is the most common cause. The crossed eye “turns off” to avoid double vision, and the child uses only the better eye.
- Uncorrected refractive errors where one eye is out of focus because it is more nearsighted, farsighted or astigmatic than the other is another cause.The blurred eye “turns off.”Amblyopia can also occur in both eyes if they are both blurred.
- An eye disease that causes clouding of an eye such as a cataract, or an optic nerve or retinal abnormality are less common but often more severe causes of amblyopia.
Treatment to Prevent Vision Loss
Early diagnosis and treatment is critical to preventing vision loss due to amblyopia.The earlier the treatment, the better the prognosis for reversing vision loss. The best time to correct amblyopia is during infancy or early childhood. Sometimes amblyopia treatment is started and/or continued into the teenage years.
Before treating amblyopia, it is often necessary to first treat the underlying cause.Glasses may be prescribed to correct focusing errors.Often glasses alone do not improve the child’s vision, and patching is necessary.This involves covering the good eye to force the child to use and strengthen the amblyopic eye.It may be used for just a few weeks or into the teenage years with a regimen to be determined by the pediatric ophthalmologist.
Sometimes amblyopia is treated by using medication – eye drops or ointment – to intentionally blur the vision of the good eye to force the weaker one to work.
In addition, surgery may be performed on the eye muscles to straighten the eyes, helping them to work together better. Patching is often continued after surgery as well.Surgery can also be used in certain conditions such as correcting cataracts and other abnormalities that could be the cause of the amblyopia.
Left untreated, an amblyopic eye may never develop good vision and may even become functionally blind.