Pushing the limits of artificial vision

The field of neural prostheses has made significant strides toward restoring damaged or lost nervous system function for millions of people. These advances have led to the development of selective electrical interfaces that communicate directly with nerve cells to modulate neural processes rationally. The first neural prosthesis developed was the cardiac pacemaker, which has become pervasive in society. The pacemaker also provides the promise that such an approach can address higher order neural dysfunctions. Technologies borrowed from the semiconductor industry have allowed researchers to micro fabricate devices with active elements on the length scale of nerve cells. This size capability has led to the development of the cochlear implant, which has restored hearing in thousands of deaf patients. Restoring more complex sensory functions, such is vision, provides greater engineering challenges, but achieving them is within our grasp. Current approaches to achieving artificial vision are discussed, along with strategies being used to push the capability limits of these prostheses even further.