Amblyopia, sometimes referred to as “lazy eye” occurs when the visual area of the brain does not develop properly for one eye. This can happen when the prescription is much higher in one eye than the other, or when one eye turns in or out (strabismus). Amblyopia leads to a loss of clarity and vision in one eye, even when the correct prescription is in your glasses. If not caught in childhood, this visual impairment becomes permanent.
Just like learning to walk and talk, the brain has to learn how to see. When one eye has a much higher prescription, the image from that eye is always blurrier than the other eye. The brain begins to pay more attention to the eye that has clearer vision, or the straight eye. Then, the brain area devoted to the “bad” eye does not develop the ability to see as well as the other eye.
The first treatment for amblyopia is to begin wearing glasses, which gives the “bad” eye a clear image, and allows the brain to start learning to see with that eye as well. Vision can also be improved with patching the “good” eye to force the brain to pay attention to the other eye. Surgery is usually required for strabismus. The younger the patient is when they begin wearing glasses, the better their outcome will be. By the age of 12, the visual system has matured, and there is little room for improvement.