Jens Naumann was 17 when an accident sent a fragment of metal from a railway line flying into his left eye. Three years later, a metal sliver from a snowmobile clutch destroyed his right eye, plunging him into total darkness. Naumann’s book Search for Paradise recounts his desperate quest back to the light, primarily as biomedical engineer William Dobelle’s “patient alpha.” In the 1970s, Dobelle had shown that electrically stimulating visual brain areas (the visual cortex) caused people to perceive spots of light, or “phosphenes.”