Strabismus is a term used to describe defects of the eye muscle system. Esotropia is the deviation of one eye toward the nose. Exotropia is the deviation of one eye toward the temporal side of the face. Hypertropia is the deviation of one eye upward.
Deviations downward are very rare.
Early diagnosis and occlusion are the best first steps in preventing amblyopia. Since the muscles of the eyes are responsible for coordinated movements and binocular vision, strabismus should be identified and treated as early as possible. The younger a child is, the better the prognosis. Preschool vision screening is highly desirable.