APA Dictionary of Psychology

n. any chronic abnormal alignment of the eyes, making normal binocular fixation and thus binocular vision impossible. Because strabismic eyes look in different directions, they give the brain conflicting messages, which may result in double vision. Alternatively, the brain may simply ignore, or suppress, one eye’s view altogether. The most common form of strabismus occurs horizontally: One or both eyes deviate inward (convergent strabismus, see cross-eye) or outward (divergent strabismus). However, the deviation may be upward (hypertropia), downward (hypotropia), or in rare cases, twisted clockwise or counterclockwise (cyclotropia). Also called heterotropia; squint. —strabismic adj.