NPR's All Things Considered has a nice piece on Louis Braille, a Frenchman who, having been blinded himself at the age of three, developed a reading and writing system for the blind that's based on various combinations of six raised dots that enabled blind people to read and write.
My favorite children's biography on Braille is Russell Freedman's Out of Darkness. The following is a review from Children's Literature:
This is a fascinating and inspirational, but not saccharine, biography of a young man who changed the world for the blind. Newbery-winner Freedman has a deft touch with history, writing it as though it were just any other great story to be told. He uses evocative details to explain the blind child's experience of Paris, such as "the rumble of wheels and clicking of hooves as carriages rolled past on the cobblestone pavement" or "flags flapping in the breeze along the Champs-Elysees...the gay laughter and swish of silk as fashionable ladies strolled by...the rhythmic crunch of a soldier's boots." Kids will be particularly impressed by the students' quiet but unshakable rebellion at the Royal Institute for Blind Youth.