Congenital strabismus is present at birth or develops within the first six months of life. If strabismus develops after six months of life, it is considered to be acquired strabismus. Some forms of strabismus are the result of abnormally functioning eye muscles, or nerves that stimulate an eye muscle; this is known as paralytic strabismus because a muscle is believed to be paralyzed. There are also medical conditions that can cause an eye muscle to be too tight or restricted, causing restrictive strabismus. Some people are born with a special form of strabismus that results from unique eye muscle, or eye muscle nerve abnormalities.
If an eye is crossed inward toward the nose, esotropia exists. If an eye is turned away from the nose (toward the ear), exotropia exists. If an eye is turned upward or downward, a hypertropia or hypotropia, respectively, exists.
Who Gets Strabismus?
