What are crossed eyes and lazy eye? — Crossed eyes is a condition in which the eyes don’t line up with each other, and don’t look in the same direction. The term doctors use for this is “strabismus.”
Lazy eye is a condition in which 1 eye doesn’t see as well as the other eye. The term doctors use for this is “amblyopia.”
These conditions happen much more often in children than in adults. Crossed eyes can run in families.
If your child has either of these conditions, it’s important to get treatment as early as possible. People who don’t get these conditions treated in childhood can have life-long vision and eye problems.
What causes these conditions? — Crossed eyes is caused by a problem with the muscles that make the eyes move. Different conditions can cause problems with the eye muscles. Some babies are born with crossed eyes.
The most common cause of lazy eye is crossed eyes. That’s because when someone has crossed eyes, each eye sees and sends a different image to the brain. This is confusing for the brain, so the brain ignores the images from 1 eye. Over time, the ignored eye becomes weaker and doesn’t see as well.
Other eye problems can also cause lazy eye.
What are the symptoms of crossed eyes and lazy eye? — When people have crossed eyes, their eyes don’t line up or move together (figure 1). This can happen all the time or only sometimes, such as when a person is tired.
In lazy eye, the vision in 1 eye is weaker than in the other eye. This can cause double vision and trouble with “depth perception” (seeing objects as “3D” instead of flat).
These symptoms can be hard to spot, so parents might not notice them. Many times, a child’s doctor or nurse first notices these symptoms during a routine check-up.
Will my child need tests? — Probably not. Your child’s doctor or nurse should be able to tell if your child has crossed eyes or lazy eye (or both) by talking with you and doing an exam. During the exam, he or she will check how your child’s eyes see and move.
The doctor or nurse might have your child see an eye specialist (called an ophthalmologist) for a more detailed eye exam.
How are these conditions treated? — Helping your child see clearly is the first step in treating both of these conditions. This usually involves having your child wear glasses.
Further treatment depends on your child’s condition and its cause.
Treatment for lazy eye involves making the weaker eye work harder so that it can get stronger. To make the weaker eye work harder, the doctor can:
Put a patch over your child’s stronger eye so that eye can’t see
Prescribe eye drops for you to put in your child’s stronger eye to make the vision in that eye blurry
Treatment for crossed eyes involves ways to make the eyes line up and work together. The doctor can do this by using special glasses, eye drops, or eye patches.
If these treatments don’t work, or if your child has severe crossed eyes, he or she might need surgery to fix the eye muscles.
After treatment, your child should see the doctor for regular follow-ups. That’s because these conditions sometimes come back.