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Blinded by the Light
by Steve Steinberg
New artificial retina technology relies on solar cells to bring sight.
An innovation that's closer to literally seeing the light of day is the Artificial Silicon Retina (ASR) invented by Optobionics (www.optobionics.com) cofounders Alan and Vincent Chow.
Age-related macular degeneration and retinitis pigmentosa are the two leading causes of untreatable blindness. Both conditions affect the retina's ability to sense light. The nerves that carry these stimuli to the brain work fine; they just don't have any information to deliver. Enter the ASR, a tiny disk measuring 3mm in diameter and 1/1,000 of an inch thick. It's made up of thousands of microscopic solar cells that act as light receptors, which convert light energy into electrical impulses that are then passed along to the brain.
Unlike other artificial retinas currently in development, the ASR is implanted between the layers of the retina instead of being attached to its surface. The Chow brothers say they believe the benefits are twofold: First, the subretinal area is a secure place for such a delicate chip. Nestled between the layers of the retina, it's less likely to get jostled or fall out of place. Second, the location allows the ASR to receive the greatest amount of stimulation. As a result, no other external hardware or headset-mounted cameras are necessary.
Right now, the ASR is designed to let the user make out rough shapes in shades of black and white. Higher quality, better resolution, and even color are possible in the future; it's just a matter of how many more cells can fit on the disk. Preliminary testing is going well, and Optobionics plans to begin human testing within a year. Look for the Artificial Silicon Retina in four to five years.
Date last modified 3/26/2000