Amblyopia, commonly known as lazy eye, occurs when there is a lack of vision in one eye because the eye and the brain are not working together. Amblyopia normally only affects one eye – resulting in the amblyopic eye pointing away from the other appearing “lazy.”
A lazy eye may result from a strabismus (crossed-eye), a difference in nearsightedness or farsightedness between eyes, as well as other pre-existing eye conditions such as cataracts, ptosis (drooping of the upper eyelid) and refractive problems. Generally, when the eyes are not working together sending identical images to the brain, the brain may start to ignore the image from the amblyopic eye. The brain’s natural tendency is to ignore the off-focus image, leaving the eye that produces it underused and weak. After time, this weakened eye may remain out of position, resulting in lazy eye.
Amblyopia generally develops early, usually before age 6, and symptoms may not always be obvious. The earlier it is diagnosed and treated, the better. For this reason, it is recommended that children receive a full eye exam at six months and again at three years. Symptoms of lazy eye include:
- Eyes that point in different directions
- Significant favoring of one eye
- Poor depth perception
- Poor vision in one eye
With early diagnosis and treatment, improved sight in a lazy eye can be accomplished. However, in the worst cases, an untreated eye can be left functionally blind.
Treatments for lazy eye include:
Patching or covering the strong eye: this method forces the weaker eye to work harder, naturally strengthening its ability to move and focus
Contact lenses and eyeglasses: corrects the discrepancy of near or farsightedness between the eyes
Surgery: Realigns muscles in the eyes, a more expensive and risky option than other forms of treatment
Although vision improvements are possible at any age with proper treatment, early detection and treatment offer the best possible results. In many cases, lazy eye surgery will provide cosmetic benefits only and does not improve the patient’s vision. Treatment options that are directed specifically toward vision improvement should be exhausted before eye muscle surgery is considered.