title: The electrical stimulation of the retina by indwelling electrodes.
abstract: Chronically implanted intraocular electrodes were  used to stimulate visual cortical responses to current passage through the retina. Electrical current threshold for the light-adapted cat retina lies in the region of 30 to 100 X 10(-6) amps. for the conditions used. Dark adaptation caused a large threshold increase. Retinal excitability also decreased when electrical stimuli were delivered more often than one per 5 seconds. Effective charge-density threshold was moderately greater than reported for frogs and humans.
mesh_terms: D000818:Animals; D002415:Cats; D003623:Dark Adaptation; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D012160:Retina / Q000502:physiology*; D013045:Species Specificity; D013997:Time Factors; D014793:Visual Cortex / Q000502:physiology*