Retinal degenerative diseases, caused by progressive degeneration of the light-sensitive photoreceptors in the retina, is one of the major causes of vision loss and blindness, affecting tens of millions of people worldwide. Although the rods and cones which are the light-sensitive cells of the retina have completely degenerated, the neural circuitries connected to the brain are mostly well preserved, providing the opportunity to restore vision by directly stimulating the retinal neurons.
Source: Medical Xpress