Reaching the summit of Mount Everest is a triumph for any climber, but for Erik Weihenmayer, the accomplishment is even more impressive. That's because he is blind. Born with a rare eye disease, Mr. Weihenmayer lost his sight at age 13 and later discovered a sense of freedom through climbing. Over the years, the 50-year-old has reached the highest peaks on seven continents and also kayaked the Colorado River through the Grand Canyon. A former schoolteacher, Mr. Weihenmayer co-founded No Barriers, a nonprofit organization that teaches outdoor skills to those with physical challenges. "Growing up in Connecticut, my Dad would drive me three hours to Massachusetts once a month to this adventure program for the blind, [said Mr. Weihenmayer]. "They took us to New Hampshire and we rock climbed on these beautiful granite rock faces. It was very tactile. That's what I really loved about it. You can feel all these little knobs and cracks and fissures and little dishes in the rock. So you're problem-solving with your hands and feet as your eyes. You had to put your body in all these cool, acrobatic positions to get yourself from point A to point B and you're trying to solve this puzzle that's embedded in the rock. I loved the great adventure. I got to the top and I could hear the valley below me. I could hear the wind blowing through the trees. And I thought this is so stunning. This is what I want out of my life."