Amblyopia (also called lazy eye) is a type of poor vision that happens in just 1 eye. It develops when thereís a breakdown in how the brain and the eye work together, and the brain canít recognize the sight from 1 eye. Over time, the brain relies more and more on the other, stronger eye ó while vision in the weaker eye gets worse.
Itís called ďlazy eyeĒ because the stronger eye works better. But people with amblyopia are not lazy, and they canít control the way their eyes work.
Amblyopia starts in childhood, and itís the most common cause of vision loss in kids. Up to 3 out of 100 children have it. The good news is that early treatment works well and usually prevents long-term vision problems.
Amblyopia starts in childhood, usually between ages 6 and 9. Identifying and treating it before age 7 brings the best chances of fully correcting the condition.
Common symptoms include:
A child might be more likely to have a lazy eye if they:
Ophthalmologists diagnose amblyopia by checking to see if vision differs between the two eyes. To check a baby's or young child's vision, the ophthalmologist may cover one of the child's eyes and watch how well they can follow a moving object. The doctor may also watch how the child reacts when one eye is covered. If one eye has amblyopia and the other is covered, the child may try to look above or below the patch, pull it off or cry.
The ophthalmologist will do a complete medical eye exam, looking for other eye problems that could be affecting vision.
Poor vision in one eye does not always mean a child has amblyopia. In some cases, wearing glasses to correct a refractive error in one eye can improve vision.
If thereís a vision problem causing amblyopia, the doctor may treat that first. For example, doctors may recommend glasses or contacts (for kids who are nearsighted or farsighted) or surgery (for kids with cataract).
The next step is to re-train the brain and force it to use the weaker eye. The more the brain uses it, the stronger it gets. Treatments include:
Wearing an eye patch on the stronger eye. By covering up this eye with a stick-on eye patch (similar to a Band-Aid), the brain has to use the weaker eye to see. Some kids only need to wear the patch for 2 hours a day, while others may need to wear it whenever they're awake.
Putting special eye drops in the stronger eye. A once-a-day drop of the drug atropine can temporarily blur near vision, which forces the brain to use the other eye. For some kids, this treatment works as well as an eye patch, and some parents find it easier to use (for example, because young children may try to pull off eye patches).
After your child starts treatment, their vision may start to get better within a few weeks. But it will probably take months to get the best results. After that, your child may still need to use these treatments from time to time to stop amblyopia from coming back.
Itís important to start treating children with amblyopia early ó the sooner the better. Kids who grow up without treatment may have lifelong vision problems. Amblyopia treatment is usually less effective in adults than in children.