Blindness is a major form of disability in the world. Loss of vision clearly compromises quality of life, and reduces independence for most patients. The relatively high incidence of blindness and the impact of blindness on quality-of-life compel many researchers to seek new treatments for blindness. Recent experimental treatments, such as gene therapy, nerve cell transplantation, and growth factors have not been successful in restoring visual perception to blind patients. The only experimental method, which has successfully restored visual sensation to otherwise irreversibly blind patients is electrical stimulation of the retina, optic nerve, or brain with a prosthetic device. A prosthesis is an artificial device that is designed to replace the function of a damaged or lost part of the body. The opportunity to use prosthesis to restore vision to the blind is based on perceived opportunities that would arise by stimulating the afferent visual system at one of the several locations. A visual prosthesis using current technologies will produce visual sensations that consist of a matrix of phosphenes to encode some of the normal visual features.This assay presents the underlying physiologic principles of artificial vision, discusses three contemporary approaches; (retinal, optic and cortical) to restoring functional vision in the blind and concludes by presenting several relevant questions to vision prostheses.