Research efforts worldwide are developing microelectronic visual prostheses aimed at restoring vision for the blind. Various visual prostheses using neural stimulation techniques targeting different locations along the visual pathway are being pursued. Retinal prostheses have proved to be capable of offering blind subjects in advanced stages of outer retinal diseases the opportunity to regain some visual function. With relatively low-density retinal implants, simple visual tasks that are impossible with the blind subject’s natural light perception vision can be accomplished. Blind subjects can spatially resolve individual electrodes within the array of the implanted retinal prosthesis and can use the system to discriminate and identify oriented patterns. This chapter reviews progress in the development of visual prostheses including visual cortex and optic nerve stimulation devices and retina stimulation devices such as epiretinal, subretinal, and extraocular implants. Second Sight Argus 16 and Argus II 60-electrode Retinal Implants are described. Some engineering challenges for the development of visual prostheses, especially retinal prostheses, are discussed.