The fight against visual impairment is being taken into the silicon age.
Optobionics Corporation of Illinois has tested a 2mm microchip that is mounted behind the retina. Its 5,000 tiny solar cells stimulate the optic nerves when light falls on them. Big improvements in sight are reported, with no side-effects.
The Dobelle Institute, Long Island, offers an Artificial Vision System in which 100 electrodes are attached to the brain surface. For about dollars 100,000 you can retrieve some sight, even if you've lost your eyes entirely, although seizures have been reported.
At the University of Utah, Dick Normann puts an implant inside the visual cortex. It should provide a higher resolution than the Dobelle device, and its lower voltage reduces side-effects.
