Experimental study on visual sensation by electric stimulation of the optic nerve in man

Abstract

Experiments were conducted on a middle-aged male, who apart from green-blindness, had healthy visual organs.v It was clearly demonstrated that when the optic nerve was directly stimulated with faradic current, a visual sensation occurred. Under certain given conditions the sensation of light was accompanied by colours, in addition to brightness with a definite shape, and position or direction in the visual field. When the stimulus was applied again the same light sensations recurred. The duration of the sensations did not exceed 4 to 5 seconds.