Paralysis or weakness of the muscles that
control eye movements, and
dilate and contract the pupil. If there is only mild weakness, the
earliest symptom is double vision. If the muscles are actually paralyzed, it may be obvious to an observer that the eye does not move in certain directions.
Ophthalmoplegia can be produced by any condition affecting the muscles themselves or the nerves that supply them. Head injuries, stroke, meningitis, encephalitis, brain tumors, and diabetes mellitus are the usual causes. The
condition also occurs in
hyperthyroidism and myasthenia gravis. The treatment depends on the cause.