Nystagmus vs. Strabismus

(pathology) rapid involuntary eye movement, usually lateral

A rapid involuntary oscillation of the eyeballs.

involuntary movements of the eyeballs; the presence or absence of nystagmus is used to diagnose a variety of neurological and visual disorders

Nystagmus is a condition of involuntary (or voluntary, in some cases) eye movement. Infants can be born with it but more commonly acquire it in infancy or later in life.

A defect of vision in which one eye cannot focus with the other on an object because of imbalance of the eye muscles; a squint.

An affection of one or both eyes, in which the optic axes can not be directed to the same object, - a defect due either to undue contraction or to undue relaxation of one or more of the muscles which move the eyeball; squinting; cross-eye.

abnormal alignment of one or both eyes

Strabismus is a condition in which the eyes do not properly align with each other when looking at an object. The eye that is focused on an object can alternate.