Definition: Strabismus refers to a disorder in which the muscles of the eyes do not work properly. Therefore, both eyes do not look in the same direction at the same time; each eye looks at different objects at the same time. If this condition is not treated, the "weaker" eye will never see well and loss of vision may occur. The cause of strabismus may be unknown or associated with certain genetic disorders, infections, injury, or other disease. The disorder may be present at birth and referred to as congenital strabismus or develop later in life.