What Happens When a Bionic Body Part Becomes Obsolete?: Blind People with Second Sight's Retinal Implants Found Out

Barbara Campbell was walking through a New York City subway station during rush hour when her world abruptly went dark. For four years, Campbell had been using a high-tech implant in her left eye that gave her a crude kind of bionic vision, partially compensating for the genetic disease that had rendered her completely blind in her 30s. “I remember exactly where I was: I was switching from the 6 train to the F train,” Campbell tells IEEE Spectrum. “I was about to go down the stairs, and all of a sudden I heard a little ‘beep, beep, beep’ sound.”