When you're blind, being able to see even the basics of light, movement and shape can make a big difference. Both the Argus II Retinal Prosthesis, currently in FDA trials, and a system being developed by Harvard Research Fellow Dr. John Pezaris record basic visual information via camera, process it into electronic signals and send it wirelessly to implanted electrodes. The Argus II uses electrodes implanted in the eye, which could help people who've lost some of their retinal function. Dr. Pezaris' system, still in the early stages of research, would bypass the eyes entirely, sending visual data straight to the brain. Both systems will work best with people who could once see because their brains will already know how to process the information. "The visual brain depends on visual experience to develop normally," Pezaris explained.

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