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Chapters

0:00 Introduction
1:32 Causes of Strabismus
2:18 Diagnosis and treatment





Strabismus is a vision disorder in which the eyes do not properly align with each other when looking at an object.[2] The eye that is focused on an object can alternate.[3] The condition may be present occasionally or constantly.[3] If present during a large part of childhood, it may result in amblyopia, or lazy eyes, and loss of depth perception.[3] If onset is during adulthood, it is more likely to result in double vision.[3]

Strabismus can occur due to muscle dysfunction, farsightedness, problems in the brain, trauma or infections.[3] Risk factors include premature birth, cerebral palsy and a family history of the condition.[3] Types include esotropia, where the eyes are crossed ("cross eyed"); exotropia, where the eyes diverge ("lazy eyed" or "wall eyed"); and hypertropia or hypotropia where they are vertically misaligned.[3] They can also be classified by whether the problem is present in all directions a person looks (comitant) or varies by direction (incomitant).[3] Diagnosis may be made by observing the light reflecting from the person's eyes and finding that it is not centered on the pupil.[3] This is known as the Hirschberg reflex. Another condition that produces similar symptoms is a cranial nerve disease.[3]

Treatment depends on the type of strabismus and the underlying cause.[3] This may include the use of glasses and possibly surgery.[3] Some types benefit from early surgery.[3] Strabismus occurs in about 2% of children.[3] The term comes from the Ancient Greek word στραβισμός (strabismós), meaning 'a squinting'.[4] Other terms for the condition include "squint" and "cast of the eye".[5][6][7] "Wall-eye" has been used when the eyes turn away from each other.[8]