Amblyopia (Lazy Eye)

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It's normal for a newborn's eyes to wander or cross occasionally during the first few months of life. But by the time a baby is 4 to 6 months old, the eyes usually straighten out. If one or both eyes continue to wander in, out, up, or down — even once in a while — it's probably due to a condition called strabismus.

Strabismus usually can be corrected when found and treated early. Waiting too long or not treating it can lead to permanent vision loss.

About Strabismus

Strabismus is when eyes don't line up or when one or both eyes wander. The eyes may turn inward (called esotropia or "cross-eyed"), outward (exotropia), up (hypertropia), or down (hypotropia). Sometimes strabismus is noticeable all the time. But other times it's only noticeable when a child is tired or looking at something very closely.

Strabismus can be present at birth or develop in childhood. Often, it's caused by a problem with the muscles that move the eyes, and can run in families.

Most kids with strabismus are diagnosed when they're between 1 and 4 years old. Rarely, a child might develop strabismus after 6 years of age. If this happens, it's important for the child to see a doctor right away to rule out other conditions.

How Vision Is Affected

When eyes don't line up together, the straight or straighter eye becomes more dominant. The vision strength (acuity) of this eye remains normal because the eye and its connection to the brain are working as they should. The misaligned or weaker eye, however, does not focus properly and its connection to the brain is not formed correctly.

If strabismus is not treated, the brain eventually will ignore the visual images of the weaker eye. The vision may be blurry or a child may not be able to see in 3D (called depth perception). This change in vision is called amblyopia or "lazy eye." These problems can be permanent if they're not treated.

Signs & Symptoms

Most kids with strabismus don't complain of eye problems or notice changes in their vision. Usually, it's a family member, teacher, or health care provider who notices that the eyes are not straight.

Some kids may complain of double vision (seeing two objects when there's only one in view) or have trouble seeing things in general. Younger children who aren't talking yet may squint a lot and turn or tilt their heads in an attempt to see more clearly.

If your child has any of these signs or symptoms, tell your doctor. He or she can refer you to a pediatric ophthalmologist for care, if needed.


Treatment for strabismus may include:

  • eyeglasses
  • eye patching
  • eye drops
  • eye muscle surgery

Sometimes, wearing eyeglasses is enough to straighten out the eyes. If not, a child might be given an eye patch to wear over the straight eye for a few hours a day. This patch makes the weaker eye do the "seeing" work. Over time, the muscles and vision in the weaker eye become stronger.

For parents of babies and toddlers, using an eye patch can be challenging. But most kids get used to the patch and wearing it just becomes part of their daily routine, like getting dressed in the morning.

Sometimes, though, a child will refuse to wear an eye patch. In these cases, eye drops (called atropine drops) might be used instead. Just as eye patching blocks the vision in the straight eye, the atropine drops temporarily blur out vision in that eye. This makes the weaker eye work harder so that eye muscles and vision becomes stronger.

If eyeglasses, eye patching, and/or atropine drops do not fix a child's strabismus, eye muscle surgery may be recommended. Surgery involves loosening or tightening the muscles that cause the eye to wander. Most kids can go home the same day of surgery.


Kids with strabismus usually won't have permanent vision loss if the condition is treated early. This is important because key connections form between the eyes and the brain by about 8 years old.

The earlier strabismus is diagnosed and treated, the better a child's chances are of having straight eyes and developing good vision and proper depth perception. Studies show, however, that older kids and teens (and even many adults with strabismus) can still benefit from treatment.

The social aspect to strabismus also should not be overlooked. Aligned eyes are important for a healthy self-image in adults and kids.

Reviewed by: Amy W. Anzilotti, MD
Date reviewed: October 20, 2016