Electronic chips have already achieved impressive results in bringing hearing to some deaf people by way of an implant in the inner ear. Now researchers are putting effort into developing ways to use electronic chips to take the place of lost photoreceptors, which respond to light. These then stimulate the output neurons of the retina to send signals to the brain. Progress has been reported and demonstrated, but this research is very much in its infancy and it has a long way to go before useful vision is obtained. Apart from the quality of visual image attainable, whether implants into the very delicate neural retina would be stable in the longer term is as yet an unknown.