Today, we use Braille not only to write words in all languages,
but also to write math and music. Blind people send Braille greeting
cards, wear Braille watches, type on Braille keyboards, and toke
elevators with Braille controls. Louis Braille had no idea how many
people he had helped. On the door of the house where he was born
are the words "He opened the doors of knowledge to all those who
cannot see.