In a child with normal visual development, the brain receives information from each eye separately and combines the two images to see one clear picture of the world. This “combining” of the information from the two eyes is called “fusing” or “fusion.”
Amblyopia occurs when the brain is unable to “fuse” or combine the information coming from both eyes. The brain learns to ignore or “suppress” the information from one eye. This leads to a lack of development or deterioration of the vision in the eye that is not being used. Amblyopia is caused by a crossed eye or drifting-eye condition called strabismus or by unequal optical prescriptions in the two eyes.
There is a long standing misconception that amblyopia cannot be treated beyond a certain age. Recent studies have shown that amblyopia can be treated effectively at almost any age.
Generally, amblyopia will only develop in children if the causative problem starts before 6 years of age. Fortunately, however, amblyopia can be treated effectively at almost any age. There is a long standing misconception that amblyopia cannot be treated beyond a certain age. Numerous recent studies have shown that this is not true.
The term that is sometimes used when referring to amblyopia is “lazy eye.” The problem is really in the brain, when both eyes are not able to be used together and the brain shuts off or ignores the information from one eye. In addition to reduced clarity of vision in the eye with amblyopia, other eye brain functions such as depth perception, tracking, and focusing are affected.
How is Amblyopia Treated?
Glasses, patching of the good eye for several hours a day, atropine eye drops, and vision therapy are all treatment options for amblyopia. The goal is to maximize clarity of sight (visual acuity), to normalize the tracking and focusing skills of the amblyopic eye, and to allow the brain to use both eyes together. When a child develops good binocular vision after amblyopia treatment, the chances of maintaining long term improvements are much better. When a child needs patching therapy for amblyopia, studies have shown that shorter periods of patching each day are usually as effective as longer or all day patching.