How important can a fifteen-year-old boy's work be? Well, Louis Braille's work changed the world. Born in a small town near Paris in 1809, shortly after his third birthday Louis blinded himself in one eye while playing with a sharp pointed tool in his father's workshop. He soon lost the sight in his other eye when the infection  spread. He wanted to go to school, but in his small town there was no school for him. At that time, blind people did not get any school education. Braille went to Paris to study, but there were few books for the blind. Louis knew that books were the key to learning. He struggled with ideas for three years. Finally, at fifteen, he invented an alphabet made with raised dots . Blind people could "read" by feeling the patterns of the dots. Being able to read Braille allows blind children to learn together with the sighted at school, and go on to get jobs. It allows people who lose their eyesight to continue to read, learn and get information. It took Braille   _   to invent the alphabet.
three years six years fifteen many years.