Canadian couple Edith Lemay and Sebastien Pelletier have four children. Mia, the eldest, was diagnosed with retinitis pigmentosa, a rare genetic condition that causes a loss or decline in vision over time. Two of their sons were soon diagnosed with the same genetic condition. "There's nothing you can really do," says Lemay, explaining that there is currently no cure or effective treatment to slow down the progression of retinitis pigmentosa. "We don't know how fast it's going to go, but we expect them to be completely blind by mid-life." Once they came to terms with the news, the couple focused their attentions on helping their children build the skills they'd need to navigate their way through life. "I thought, 'I'm not going to show her an elephant in a book, I'm going to take her to see a real elephant," Edith Lemay explained. "And I'm going to fill her visual memory with the best, most beautiful images I can." She and her husband soon began making plans to spend a year travel...