ABSTRACT
The possibility of restoring vision to blind patients using electricity began with the discovery that an electric charge delivered to a blind eye produces a sensation of light. This discovery was made by LeRoy in 1755 [1]. However, it was not until 1966 that the first human experiments in this field began with Giles Brindley’s experiments with electrical stimulation of the visual cortex [2]. He used 180 cortical surface electrodes on patients, who were then able to perceive spots of light called “phosphenes,” but they were ill defined and could not be combined to make an image. This did fail to produce useful vision in these patients. Similar experiments by William Dobelle in 1974 produced essentially the same results [3,4].
