Lazy Eye (Amblyopia)
What Is It?
Lazy eye, also called amblyopia, is an eye problem that can occur in growing children. In the typical child with lazy eye, the right and left eyes have significantly different qualities of vision, so that the images produced by one eye are weak or distorted compared with the images produced by the other eye. Because the weak eye sends poorly focused images to the brain, the brain learns to depend on the stronger eye for its visual information. If this situation is not corrected, the brain eventually chooses to accept images from the stronger eye alone and ignores images from the weak one. In other words, the weak eye doesn't learn to see.
The brain's choice usually is made early in childhood when the brain's visual pathways are still developing. This critical period begins at birth and probably ends sometime between ages 6 and 9. If lazy eye is not diagnosed and treated within this critical period, the brain may choose to ignore the weak eye permanently, causing a lifelong loss of vision on that side.