Since losing his vision at age 13, Erik Weihenmayer has summited Mount Everest, white-water rafted and climbed frozen waterfalls. But making soup in his kitchen presented a unique challenge. On a frozen waterfall he could tap his ax against the ice to get a feel for its density, but in the kitchen, he had no way to differentiate between cans of tomato and chicken noodle. Mr. Weihenmayer, 49 years old, found a solution in Microsoft Corp.'s Seeing AI, a free app for the visually impaired. Among other things, the app can recognize faces, identify money, read handwriting and scan bar codes to differentiate between cans of soup.

The climbers at Earth Treks gym, in Golden, Colorado, were warming up: stretching, strapping themselves into harnesses, and chalking their hands as they prepared to scale walls stippled with multicolored plastic holds. Seated off to one side, with a slim gray plastic band wrapped around his brow, Erik Weihenmayer was warming up, too--by reading flash cards. "I see an'E' at the end," he said, sweeping his head over the top card, from side to side and up and down. Weihenmayer moved triumphantly on to the next card. Erik Weihenmayer is the only blind person to have climbed Mt. 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.