What is Amblyopia?
Amblyopia (lazy eye) is the loss or lack of development of vision in an eye that is unrelated to any eye health problem. The brain, for some reason, does not acknowledge the images seen by one of the eyes (the amblyopic eye). Reduced vision due to amblyopia is not correctable with lenses alone.
Amblyopia is generally the result of poor early visual development, and as such, usually occurs before the age of eight.
Children will adapt to visual problems, by suppressing or blocking out the image. The vision can often be improved with treatment if caught early enough (studies vary, but typically treatment before age 6 is most effective).
What Causes Amblyopia?
Amblyopia usually results from a failure to use both eyes together. It can be caused by the presence of strabismus (crossed-eyes), unequal refractive error (farsightedness or nearsightedness), or a physical obstruction of vision (cataract).
If there is a large enough difference in the degree of nearsightedness, farsightedness or astigmatism between the two eyes, or if the eyes are crossed, the brain learns to ignore one image in favor of the other.
Normally, the images sent by each eye to the brain are identical. When they differ too much, the brain learns to ignore the poor image sent by one eye and “sees” only with the good eye.
The vision of the eye that is ignored becomes weaker from disuse.
How is Amblyopia Diagnosed?
A comprehensive optometric examination can determine the presence of amblyopia. The earlier it is diagnosed, the greater the chance for a successful treatment.
Since amblyopia occurs only in one eye, the good eye takes over and the individual is generally unaware of the condition. That is why it is important to have your child’s vision examined at about six months, at age three and again before he or she enters school.
How is Amblyopia Treated?
Corrective lenses, prisms and/or contact lenses are often used to treat amblyopia. Covering or occluding the better eye, either part-time or full-time, may be used to stimulate vision in the amblyopic eye. In addition, a program of vision therapy may be prescribed to help improve vision.
If the underlying issue is droopy eyelid or cataracts, surgery may be needed to correct this condition. It is absolutely imperative that treatment is sought after signs of symptoms. Amblyopia becomes difficult to treat later on in life.