RESTORING vision with silicon chips designed to be implanted in the eye may
be even harder than anyone thought. The first long-term study of such a chip has
shown that it corrodes within a year.
Various groups are working on devices for restoring limited vision to people
whose light-sensing cells have been damaged by disease. Most are microchips
designed to be implanted under the retina. When they detect light, they directly
stimulate the underlying retinal neurons via an array of microelectrodes.
The chips tested by Martin Stelzle of the Natural and Medical Sciences
Institute in Reutlingen, Germany, and his colleagues…
