Lazy eye (amblyopia) in children

A lazy eye is when the vision in one of your eyes does not develop properly. Doctors also call it amblyopia.

Without treatment, your brain will learn to ignore the image that comes from the weaker eye. This can cause permanent vision problems.

Lazy eye symptoms

Amblyopia begins in childhood, usually between the ages of 6 and 9. Identification and treatment before 7 years of age gives the best chance for a complete cure of the disease.

Common symptoms include:

Trouble telling how near or far away something is (depth perception)
Squinting or shutting one eye
Head tilting

Causes of lazy eyes

Doctors don't always know what's behind some cases of amblyopia. Reasons may include:

Refractive errors. One eye can have much better focus than the other. The other eye may be nearsighted or farsighted. Or he may have astigmatism (distorted or blurry vision). When your brain receives both a blurry image and a sharp image, it starts to ignore the blurry image. If this continues for months or years, the vision in the clouded eye will deteriorate.
Strabismus. This is when your eyes are not properly aligned. We could enter or exit. People with strabismus cannot focus on an image at the same time, so they often experience double vision. Your brain will ignore an image of an eye that is not aligned.
Cataract. A cloudy lens inside your eye can make things look blurry. Vision in that eye may not develop as it should.
Dropped eyelid (ptosis). A drooping eyelid can block your vision.

Risk factors for lazy eyes

A child may be more likely to have a lazy eye if they:

Were born early (premature)
Were less than average at birth
Have a family history of amblyopia or other eye conditions
Have developmental disabilities

Diagnosis of lazy eyes

All children must have their eyes tested before they reach school age. Your child's doctor or the school's vision program will check to make sure that:

Nothing blocks light from entering their eyes
Both eyes see equally well
Each eye moves as it should

If there is a problem, the doctor or school nurse may suggest that you take your child to an ophthalmologist. If you feel that something is wrong with your child's vision, even if the vision test shows nothing, make an appointment with a pediatric eye doctor.

Some eye care experts say that children should have eye exams at 6 months, 3 years, and then every year while they are in school. Ask your doctor what is right for your child.

Eye care experts test babies and young children by observing how well their eyes follow a moving object. They can also close one eye at a time and check the child's reaction.

For older children, the doctor closes one eye and uses pictures and letters to check their vision.

Lazy eye treatment

It is important to start treatment for amblyopia as early as possible. Depending on the cause, this may include:

Correct underlying vision problems such as nearsightedness, farsightedness or astigmatism. Most children with amblyopia also need glasses to help their eyes focus.
Surgery if a cataract is blocking light from their eyes or if a squint is preventing their eyes from moving as they should
Put a patch on the strong eye to force his brain to use the weak eye. At first, it will be difficult for your child to see. Their vision will improve, although this may take weeks or months. After that, they will not have to constantly wear a band-aid. But sometimes, when children start using both eyes again, they partially lose sight in the weak eye. If this happens, they may need to put the patch back on.
Eye drops with a medicine called atropine, which clouds the strong eye so your child doesn't need to wear a bandage. It also causes their brain to use the weak eye.
A Bangerter filter put on the lens of the stronger eye to blur his vision, so he has to use the weaker eye.

Lazy eye in older children and adults

Some teens and adults with lazy eye have an effective treatment. But that may not work when a child's vision is fully developed, around age 7 to 9. If one eye remains fuzzy and he loses sight in the stronger eye later in life, he may have lifelong problems.

Complications for lazy eyes

If treatment is started too late, the loss of vision due to amblyopia can be permanent because the connections in the body's visual system do not form properly.

With early diagnosis and treatment, most children have almost complete recovery of vision. Make sure your child has an eye exam as early as possible. Follow your doctor's advice about treatment, even if it's hard to get your child to do things like wear a band-aid every day.