Eye Health Center

Eye Health and Strabismus

Strabismus, also known as crossed eyes, is a condition in which the eyes don't look towards an object together. One of the eyes may look in or out, or turn up or down. The eye turning away can occur all of the time or only sometimes, such as during stressful situations or illness.

What Causes Strabismus?

Some people are born with eyes that do not align in the usual way. This is called congenital strabismus. In many children, there is no clear cause of strabismus. In some cases, it is a result of a problem with the nervous system, especially the part that controls the muscles of the eyes. It may be due to a tumor or disorder in the infant eye. If it is not corrected, strabismus can continue into the adult years. Most adults who have strabismus were born with it.

If strabismus does not appear until later in life, it will cause double vision. If the eyes become misaligned in an adult who did not have strabismus as a child, it could be a sign of a serious condition such as a stroke. A sudden misalignment of the eyes, or double vision, are important reasons to see a doctor immediately.

Someone who is born with strabismus will avoid double vision by covering or closing one eye or alternating the eyes. Depth perception and peripheral vision (vision off to the side) may be affected. Eyestrain and headaches can occur. The patient may turn their head in unusual ways in order to see in certain directions.

How Is Strabismus Treated?

If strabismus is suspected, a pediatric eye doctor should be consulted. Vision therapy may be recommended to help a person correct his or her vision or strengthen the eye muscles. This therapy may help train a patient's brain to align his or her eyes to focus and visually process images. Vision therapy uses computerized optical devices, including lenses and filters, to develop the eye muscles. Stabismus must be treated in childhood to avoid amblyopia (lazy eye). This condition can cause permanent vision loss if not evaluated or treated in childhood. 

Is Surgery an Option to Treat Strabismus?

Yes. Surgery to correct strabismus is performed to strengthen or weaken the effect of one or more of the muscles that move the eye. The procedure is done by an ophthalmologist and, ideally, during childhood. When this procedure is performed on adults, it can usually be done under local anesthesia. (The eye is numb, but the patient is awake.)

The surgeon will first make an opening into the outer layer of the eyeball in order to reach the muscle that will be strengthened or weakened.

Strengthening the muscle usually means removing a small section from one end and then reattaching it back together at the same location. This makes the muscle shorter, which tends to turn the eye toward the side of that muscle.

"Weakening" the muscle usually means moving it back or making a partial cut across the muscle. This has the effect of making the muscle weaker, which lets the eye turn further away from the side of that muscle.

If the patient experiences double vision, it usually goes away within a few weeks after surgery as the brain adjusts to the new way of seeing.