Strabismus is any misalignment of the eyes. Eye crossing, an eye that drifts out, or having one eye higher than the other are all forms of strabismus. Strabismus can occur at birth, early childhood, or as an adult and has many different causes. Treatment of strabismus can include glasses, eye exercises, and surgery.  Strabismus in children can be a sign of other serious underlying eye disorders and should be evaluated without delay by an eye doctor experienced in childhood eye problems. Strabismus in adults can cause double vision and other problems. It can be a sign of a more serious underlying condition or can be something that has been present since childhood. It is important to know that there are almost always treatment options available to adults with strabismus.