APA Dictionary of Psychology

n. a type of strabismus (squint) in which there is a deviation of one or both eyes toward the other. The condition usually begins in infancy and is caused by deficient activity of one or more extrinsic eye muscles. Uncorrected cross-eye results in double visual images or functional amblyopia. Cross-eye can be treated surgically in most cases. Also called convergent strabismus; esotropia.