In the mid-1980s, neuroophthalmologist Joseph Rizzo III was researching retinal transplants to restore blind people's vision. One day, removing a lab animal's retina, a tissue-thin membrane that lines the back of the eyeball's interior, he had an epiphany. "The moment I made the cut, I said to myself, 'What in the hell are you doing?'" Rizzo recounts. He realized he was cutting nerve connections that are actually spared in many forms of blindness. The retina's light-sensing cells die off in retinitis pigmentosa and age-related macular degeneration, which affect millions worldwide; but the nearby neurons that ferry the signals from those cells to the brain remain intact. So Rizzo conceived of a retinal prosthesis -- an implant that would take a wireless signal from a video camera, bypass the light receptors, and stimulate the healthy nerve cells directly to feed the image to the brain. Rizzo, working at the Massachusetts Eye and Ear Infirmary and the Boston VA Medical Center, teamed up with MIT electrical engineer John Wyatt Jr. to pursue the scheme. In 1988, they launched the Boston Retinal Implant Project, which today comprises 27 researchers at eight institutions. The team has already done short-term human tests and hopes to test a permanent prosthesis by 2006. Wyatt and Rizzo recently gave TR contributing editor Erika Jonietz a peek at their progress.

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