A lazy eye, or amblyopia, is a condition in which the brain favors one eye over the other, resulting in reduced eyesight and abnormal spatial vision development.
Lazy eye is the most common cause of vision loss in children, though it only affects approximately 2% of people in the United States.
Since the other eye is still functional, individuals with a lazy eye often won’t complain about or notice blurred or poor vision, though they may have reduced reading speed and trouble with hand-eye coordination.
General Principles of Treatment
“The sooner, the better.” Younger children (less than eight years old) have a higher success rate with treatment than older children or adults. Teenagers and adults can still experience improvement, but it is generally understood that early treatment is better.
Treatment strategies primarily involve suppressing the stronger eye in some way so that the weaker eye is forced to “exercise.”
Lazy eyes result from abnormal development of the connections between the eye and the brain. Then, as the brain tries to make sense of the mismatched images from each eye, it will tend to ignore or suppress the information from the weaker eye.
Untreated, this will cause the weaker eye to become even weaker, potentially leading to permanent vision loss. But if the brain is forced to use information from the weaker eye, it can strengthen those connections and improve vision.
Refractive Correction
The first step in treatment typically will be an attempt to improve vision with glasses, contact lenses, or possibly LASIK surgery.
Some people, especially those with a high degree of refractive error, may achieve normal or near-normal vision with this step alone.
Eye Patching
The next step in treatment will be to patch the stronger eye, forcing the person to see using only the weaker eye.
While it was historically believed that “the more, the better” (meaning wear it as much as possible), it’s now understood that starting with patching for 2 hours a day is usually better and gradually increasing as needed.
Atropine Eye Drops
If eye patching doesn’t seem to help, or if the person is unable or unwilling to wear an eye patch, atropine eye drops may be prescribed as an alternative.
The underlying principle is similar to patching – obstructing the better eye, forcing the person to use and strengthen the weaker eye.
Atropine eye drops temporarily blur vision in the good eye so that the brain can learn to use the other eye.
Video Game Training
A newer treatment option for lazy eye uses specially designed video games and mobile apps to give the child a fun way to exercise and strengthen the weaker eye.
For many of the games, the player wears red-green anaglyphic glasses (like the old 3D glasses you may have worn at the movie theater) so that the game can show different game elements to each eye. For example, monsters or targets might only be shown to the weaker eye, leading the player to become more alert and responsive to what that eye sees.
If you or your child is struggling with visual impairment, you must talk with your doctor or eye care professional about the best treatment options. Early intervention is key, and there are many ways to improve vision and quality of life, even if the problem has been present for many years.