Follow Up:

Artificial sight moved a blink closer to reality recently, when scientists implanted an electronic retina into the eye of a man who had been blind for half a century. This marks a major milestone for researchers who have been pursuing the project for more than 15 years (see "Artificial Sight," Discover, August 2001). Mark Humayan, an ophthalmologist at the University of Southern California's Doheny Retina Institute, and his colleagues report that their 74-year-old patient is adapting well to his electric eye. An outside camera captures his surroundings, then radios the image to an array of 16 electrodes adjacent to retinal cells on the back of his eye. His brain is now learning to interpret the signals from those electrodes. So far, the patient can determine whether an object is in his field of view and can identify the location of someone in the room. "For someone who's been totally blind, even a little bit of vision can be very useful," Humayan says. Two more patients are in line for this phase I clinical trial. Gerald Chader, chief scientific officer of the Foundation Fighting Blindness, is guarded about the latest progress: "It's exciting, we're holding our breath—but it's a little premature yet."