Lazy eye — also called amblyopia — is a vision development disorder where an eye is incapable of attaining normal visual acuity, even with eyeglasses or contact lenses, despite no apparent eye injury or disease.
Amblyopia typically starts in infancy or early childhood and generally occurs only in one eye; but in some cases, both eyes may be affected. The most common cause of lazy eye is an eye alignment problem called strabismus — misalignment of the eyes that prevents both eyes from being used equally.
Congenital cataracts also can cause amblyopia. Performing cataract surgery on a young child with congenital cataracts often can fully correct the amblyopia or at least significantly improve the visual acuity of the affected eye(s).
However, the older a person with amblyopia becomes, the less likely it is that cataract surgery will fully restore vision in a lazy eye. But it's possible there may be some noticeable improvement in vision in an amblyopic eye after surgery. It depends on how much of the visual impairment in the affected eye is due to amblyopia and how much is due to the cataract.
Recent studies of the plasticity of the human brain have suggested that vision therapy, strabismus surgery and other measures (including cataract surgery) may be able to make some improvement in the visual acuity of an amblyopic eye in adults. Still, early intervention in childhood is much more effective in improving vision in a lazy eye.
