Crossed Eyes (Strabismus): How It Works, Explained Simply

Video Transcript

Strabismus is when the two eyes do not point in the same direction at the same time. Six small muscles attach to the outside of each eye. For the eyes to work as a pair, those twelve muscles have to be coordinated precisely by the brain. One eye may turn inward toward the nose, outward toward the ear, or sit higher or lower than the other. The turn can be constant, or it may come and go, appearing when a child is tired, unwell, or concentrating hard. In children, the brain often suppresses the image from the turned eye to avoid double vision. Left alone, that can lead to amblyopia, or lazy eye. When strabismus appears suddenly in an adult, the brain cannot ignore the second image the same way, so double vision is common. A new turn or new double vision needs prompt medical assessment. Many babies have eyes that seem to drift in the first few months, which can be normal. A turn that persists beyond about four months should be checked. Treatment depends on the cause. Glasses alone can straighten some turns, patching may be needed if vision has weakened, and surgery can adjust the muscles to realign the eyes. This video is for general education only. It is not medical advice. Ask your eye doctor what's right for you.