Erik Weihenmayer is the only blind person to have climbed Mt. Everest. He was born with juvenile retinoschisis, an inherited condition that caused his retinas to disintegrate completely by his freshman year of high school. Unable to play the ball games at which his father and his brothers excelled, he took to climbing after being introduced to it at a summer camp for the blind. He learned to pat the rock face with his hands or tap it with an ice axe to find his next hold, following the sound of a small bell worn by a guide, who also described the terrain ahead. With this technique, he has summited the tallest peaks on all seven continents.
A decade ago, Weihenmayer began using the BrainPort, a device that enables him to “see” the rock face using his tongue. The BrainPort consists of two parts: the band on his brow supports a tiny video camera; connected to this by a cable is a postage-stamp-size white plastic lollipop, which he holds in his mouth. The camera feed is reduced in resolution to a grid of four hundred gray-scale pixels, transmitted to his tongue via a corresponding grid of four hundred tiny electrodes on the lollipop. Dark pixels provide a strong shock; lighter pixels merely tingle. The resulting vision is a sensation that Weihenmayer describes as “pictures being painted with tiny bubbles.”
Image courtesy of The New Yorker.