Somewhere in Paris, in a white room, seated at a white table, a man wearing a headset reminiscent of those worn by VR gamers reached out with his right hand and placed his fingers on a black notebook. This simple motion, which he executed with confidence, was notable for one very important reason; the man had been blind for close to four decades.
What was different now was that as part of a clinical trial, genes had been injected into one of his eyes, causing neurons in the retina to produce a light-sensing protein normally found in the slimy bodies of green algae. When the black goggles he was wearing projected video images of his surroundings as a pulsed light beam onto those now-light-sensitive cells, the neurons fired, and the signal traveled up the optic nerve and into the visual processing center of the brain. The genetically modified neurons had become stand-ins for the photoreceptors he had lost many years before to a genetic disease called retinitis pigmentosa.