Braille

We all know what Braille is but most of us know very little about it. Louis Braille, a Frenchman, lost sight in one eye at the age of three when he stabbed himself in the eye with one of his father's workshop tools (I blame the parents!). He lost the sight in his other eye due to a bizarre condition called Sympathetic Ophthalmia, which is an inflammation of both eyes following injury to one of them. It's like the second eye basically swells up in sympathy! During his time at National Institute for the Blind in Paris he developed a system of six raised dots, which he finished at age 15. He released a booked titled "Method of Writing Words, Music, and Plain Songs by Means of Dots, for Use by the Blind and Arranged for Them" in 1829. Louis died in 1852, aged 43, and it wasn't until two years after his death that his invention was officially recognized.

The Braille system has six dots, arranged in a rectangle 2 dots across by three dots down. Letters are made up by the existence or absence of a dot in the six locations, allowing 64 unique characters to be displayed. In English, Braille can code the alphabet, punctuation, and some commonly used double letter and word codes (such as "th" and "and"). Strangely, numbers require a specific character to proceed the next character, which is then followed by one of the first 10 letters of the alphabet, and "A" corresponds to "1 ", "B" to "2" and so on, until "J" which corresponds to "0". Different character sets are used to code music symbols and mathematical characters.

The system of using characters and giving them an "on" or "off" value makes Braille the very first binary form of encoding characters, similar to the ASCII and Unicode character sets used by computers today. Despite being French, Braille was 150 years ahead of his time!

What I really want to know (and I'm interested in your feedback on this) is: how do blind people know where to look for writing in Braille? It is fair enough to use it in books and on medicine containers etc, but when out and about do they just feel their way over the whole surface of a door in the vain hope of finding a dimpled plaque? If they are with somebody with vision they can show them where the Braille is located, although they would be quicker just telling them what it says.