Amblyopia is a condition often called “lazy eye” where one eye has reduced visual acuity (i.e. can’t see 20/20), even with the appropriate glasses or contact lens correction. Amblyopia occurs when the brain ignores or suppresses information from one eye. This condition affects 2 to 3 out of every 100 children. According to the National Institute of Health, amblyopia is the most common cause of visual impairment among children. The two most common types of amblyopia are refractive ambylopia and strabismic amblyopia.
Refractive amblyopia occurs when there is a large difference in refractive error (a.k.a. the prescription needed to focus an image on the retina) between the two eyes. This condition develops because the images in each eye are different, or when one eye must work harder than the other to see. The differences between the pictures created by the two eyes makes it difficult to merge the two images together into one.
If the brain is faced with one blurry picture and one clear picture it will give preference to the clear picture and ignore information from the blurry one. Over time this suppression of information leads to reduced acuity. Usually the amblyopic eye will also have greater difficulty with other visual skills such as focusing, tracking, eye-hand coordination and higher levels of visual processing. In cases of refractive amblyopia, wearing the appropriate prescription is an important aspect of treatment.
The second most common cause of amblyopia is strabismus. Strabismus is a misalignment of the eyes, usually esotropia (eye turn in) or exotropia (eye turn out). When the eyes have trouble coordinating with each other and are not pointing in the same place at the same time, the brain gets confused and cannot put the images together. To avoid double vision, the brain will ignore information from one of the eyes.
New research shows that, in many cases, amblyopia can be treated at any age. Our office typically uses binocular vision and biofeedback approaches to treatment. These approaches are more advanced than passive “patching only” programs; they also recognize that the ultimate goal of any amblyopia treatment is to train the brain to coordinate and integrate information from both eyes. In other words, this is not just an “eye” problem, but is related to higher level visual functions in the brain. Visual skills that are impaired in amblyopia involve more than just visual acuity and include skills such as focusing, eye tracking, eye-hand coordination, eye teaming and depth perception. At New Horizons Vision Therapy Center amblyopia is generally treated with a combination of therapeutic lenses, home therapy activities and in-office vision therapy sessions. Each treatment plan is customized based on the patient’s needs and goals.