RP ruins peripheral vision, while macular degeneration causes a blurred or blind spot in central vision. Both conditions irreparably damage the retina, the light-sensitive patch at the back of the eye that converts images into signals and relays them the brain.
Scientists now aim to create sensitive devices that can be implanted in the eye and will let previously blind people recognize faces and read large print. These artificial retinas are still experimental and won't be available for commercial use for years, however. Currently, the Argus Two artificial retina is being tested on 17 blind people in the U.S. and Europe. In the meantime, scientists at the Energy Department's National Laboratories are creating a third-generation artificial retina, and hope to begin human trials in 2011