Strabismus, << struh BIHZ muhs, >> is an abnormal condition of the eyes in which one eye is fixed on one object and the other eye is fixed on another object. This condition is also known as heterotropia, cross-eye, and squint. Normally, the position of the eyes enables both eyes to see the same object at the same time and in the same place. In strabismus, one eye turns away from its normal position. If this eye turns inward toward the nose, the condition is known as convergent strabismus. In divergent strabismus, the eye turns outward. In supravergent strabismus, the eye turns upward or downward. Strabismus may be constant or periodic and may involve only one eye or alternating eyes.
Convergent strabismus is the most common form of strabismus. Most cases of convergent strabismus occur in far-sighted children under 4 years of age. To see clearly, far-sighted children often force their eyes together, resulting in strabismus. Strabismus is sometimes caused by weakened, overactive, or restricted eye muscles. Damaged nerve connections can also cause the condition. The tendency to have strabismus is inherited.
Strabismus can be corrected in children, especially if treatment starts early. Treatment of strabismus usually involves wearing glasses, forced development of the weaker eye, and training the eyes to function together. However, many cases of strabismus eventually require surgery or the use of drugs to weaken an overactive muscle. If strabismus is not corrected, vision in the affected eye may never develop properly or may be lost entirely.
