The eye movements of the dark-reared cat.
Cats reared in total darkness to adulthood have abnormal eye movements. A spontaneous nystagmus is found in the dark before any visual experience. The eye movements evoked by vestibular or optokinetic stimulation are less effective at compensation than for a normal cat. The vestibulo-ocular reflex (VOR) has a low gain (around 0.3) and a frequency dependent phase relation. The efficiency of optokinetic nystagmus (OKN) is poorer than for a normal cat, except for downwards stimulus movement which is followed better than normal. OKN is poorest in response to a stimulus viewed monocularly moving in the nasal to temporal direction. Neither VOR nor OKN of a dark-reared cat recover in efficiency within 5 months of the animal being brought into the light. A normal cat put into the dark for 135 days shows none of these abnormalities except an occasional spontaneous nystagmus.
D000064:Acclimatization; D000818:Animals; D002415:Cats; D003624:Darkness; D005133:Eye Movements; D008027:Light; D010775:Photic Stimulation; D012022:Reflex, Acoustic; D012025:Reflex, Pupillary; D012399:Rotation