Strabismus is a disorder in which the eyes do not line up in the same direction when focusing. The condition is more commonly known as "crossed eyes."
Alternative NamesCrossed eyes; Esotropia; Exotropia; Squint; Walleye
Causes, incidence, and risk factorsStrabismus is caused by a lack of coordination between the eyes. As a result, the eyes look in different directions and do not focus at the same time on a single point.
In most cases of strabismus in children, the cause is unknown. In more than half of these cases, the problem is present at or shortly after birth (congenital strabismus).
In children, when the two eyes fail to focus on the same image, the brain may learn to ignore the input from one eye. If this is allowed to continue, the eye that the brain ignores will never see well. This loss of vision is called amblyopia, and it is frequently associated with strabismus.
Some other disorders associated with strabismus in children include:
Strabismus that develops in adults can be caused by:
A family history of strabismus is a risk factor. Farsightedness may be a contributing factor. In addition, any other disease causing vision loss may cause strabismus.
SymptomsA physical examination will include a detailed examination of the eyes. Tests will be done to determine the strength of the eye muscles.
Eye tests include:
A neurological examination will also be performed.
TreatmentTreatment involves strategies to strengthen the weakened muscles and realign the eyes. Glasses and eye muscle exercises may be prescribed.
If the condition is caused by a lazy eye, the doctor may prescribe an eye patch. Some children may need surgery. For more information on treating lazy eye, see: Amblyopia
Expectations (prognosis)With early diagnosis and treatment, the problem can usually be corrected. Delayed treatment may lead to permanent vision loss in one eye.
Calling your health care providerStrabismus requires prompt medical evaluation. Call for an appointment with your health care provider or eye doctor if your child:
Note: Learning difficulties or problems at school can sometimes be due to a child's inability to see the blackboard or reading material.
ReferencesHatt SR, Leske DA, Kirgis PA, Bradley EA, Holmes JM. The effects of strabismus on quality of life in adults. Am J Ophthalmol. 2007 Nov;144(5):643-7.