NYSTAGMUS. OSCILLATORY MOVEMENT OF THE EYE.
This consists in spasmodic involuntary oscillation of the eyeball in a horizontal, lateral, oblique or rotary direction. In animals it has been seen in connection with poisoning and brain diseases. Johné has observed it in horses in cerebro-spinal meningitis, Wenderhold in epilepsy, and Möller in chloroform anæsthesia. Möller has further seen it in puppies with congenital microphthalmos, and Siedamgrotzky in swine which had been poisoned by herring brine.
Slight cases of functional disturbance may improve under good hygiene, open air life and tonics, cases due to poisons may recover spontaneously when such poisons have been eliminated, but those which depend on structural disorder of the brain are beyond remedy.