Are You Ready for a New Sensation?; Secrets of the Senses; Special Editions; by Kathryn S. Brown; 8 Page(s)
The flimsy strip of golden film lying on John Wyatt's desk looks more like a candy wrapper than something you would willingly put in your eye. Blow on it, and the two-millimeter foil curls like cellophane. Rub it, and the shiny film squeaks faintly between your fingers. In fact, you have to peer rather closely to spot a neat patchwork: a tiny photodiode array, designed to bypass damaged cells in a retina and, Wyatt hopes, allow the blind to see.
This small solar panel is part of a prototype retinal implant. For more than 15 years, Wyatt--an engineer at the Massachusetts Institute of Technology--and his colleagues have pursued an implant to electrically stimulate the retina. At first, even Wyatt doubted the project could succeed. The retina, he says, is more fragile than a wet Kleenex: it is a quarter of a millimeter thin and prone to tearing. In about 10 million Americans--those with the disorders retinitis pigmentosa and macular degeneration--the delicate rod and cone cells lining the retina's farthest edges die, although ganglion cells closer to the lens in the center survive. In 1988 Harvard Medical School neuro-ophthalmologist Joseph Rizzo asked Wyatt two key questions: Could scientists use electricity to jolt these leftover ganglion cells and force them to perceive images? Could they, in effect, engineer an electronic retina?