What Is Strabismus?

Strabismus—a common disorder often referred to as crossed eyes—is a misalignment of the eyes. Normally, the six tiny muscles attached to each eye assure that the eyes work in parallel; coordinated eye movement allows for three-dimensional vision and proper depth perception. Impairment of the eye muscles or the nerves that control them may prevent the eyes from focusing together, resulting in double vision. In young children—in whom strabismus is most prevalent—the brain reacts to the double image by ignoring signals from the eye that deviates more often.

If left untreated, this may result in permanent vision loss in the ignored eye (suppression amblyopia or lazy eye); a child will not simply outgrow strabismus. However, if amblyopia and strabismus are treated before the age of five or six, normal vision may be preserved. The earlier treatment is initiated, the greater the likelihood of a favorable outcome. When strabismus occurs in adults, it is often a sign of some underlying disorder.

What Causes Strabismus?

  • The cause of strabismus hasn’t been established. Impaired development of the nerves to the ocular muscles or impaired development of the muscles themselves may cause strabismus in children.
  • Hereditary factors may play a role.
  • Inappropriate growth of the "fusion center" of the brain
  • Injuries to muscles or nerves
  • Increased risk is associated with farsightedness (hyperopia).
  • In people at any age, an eye that loses vision may deviate.
  • In adults, strabismus may occur as a complication of an underlying disorder, such as diabetes mellitus, multiple sclerosis, cancer or stroke.
  • Fatigue, stress, or illness can sometimes cause temporary strabismus.

Symptoms of Strabismus

  • Appears as if the two eyes are looking in two different directions
  • Impaired vision in the deviated eye
  • Double vision
  • Faulty depth perception

Strabismus Prevention

There is no known way to prevent strabismus.

Strabismus Diagnosis

  • Eye examination by an ophthalmologist can identify strabismus.
  • Patient history and physical examination may be necessary, especially in adults, to diagnose an underlying disorder.

How to Treat Strabismus

  • Initial therapy involves attempts to force the brain to utilize the deviating eye. An eye patch or eyedrops that temporarily blur the vision may be used in the unaffected eye to encourage increased use of the amblyopic eye.
  • Eyeglasses may be prescribed to correct farsightedness and other refractive (vision) conditions.
  • Surgical repositioning of the muscles that control eye movement may be necessary to bring about realignment; more than one operation may be required.

When to Call a Doctor

  • Call a doctor or ophthalmologist if your child’s eyes seem misaligned (although occasional crossed eyes in infants less than three months old is normal and nothing to worry about).
  • Call a doctor or ophthalmologist if you develop double vision.


Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at HealthCommunities.com

Published: 09 Sep 2011

Last Modified: 02 Oct 2014