Retinal implant can restore partial sight

BBC : As part of a recent clinical trial in the UK, two men who had been completely blind for a number of years had part of their vision restored with a pioneering eye implant. Both had lost their sight to retinitis pigmentosa, a condition in which the photoreceptor cells at the back of the eye gradually cease to function. In the procedure, a microelectronic chip is placed behind the retina and connected by a fine cable to a subdermal control unit behind the ear. Light stimulates the chip to send electronic signals to the optic nerve. Although conventional vision is not restored, the patients were able to see flashes of light. Such minimal visual clues could help the visually impaired to distinguish doors and windows and enable them to orientate themselves in a room, for example.