Author David Adler writes biographies that appeal to children, scrupulously using facts about a person's life to tell an engaging story. Louis Braille was born in 1809 in a small village outside of Paris. At the age of three, he accidentally injured his eye while playing with his father's tools and soon after lost all the sight in both of his eyes. Encouraged by a local priest and his schoolteacher, Louis went on to live and study at the National Institute of the Blind in Paris in 1819, where, at the age of 11, he began to experiment with a new raised code for letters based on a 'night writing' code used by the French army. Wrote Louis in his diary, 'If my eyes will not tell me about men and events, ideas and doctrines, I must find another way.' Although Louis introduced his revolutionary braille code in 1824, the French government did not officially approve his dot system, simply called 'braille, ' until 1854 - two years after Louis's death. A memorial plaque in his village reads, 'He opened the door to knowledge for all those who cannot see. Eventually, braille became the standard system used throughout the world. Louis Braille's alphabet, along with numbers, appears in both print and braille at the back of the book.