Braille is writing system which enables blind and partially sighted people to read and write through touch. It was invented by Louis Braille (1809-1852), who was blind and became a teacher of the blind. It consists of patterns of raised dots arranged in cells of up to six dots in a 3 x 2 configuration. Each cell represents a letter, numeral or punctuation mark. Some frequently used words and letter combination also have their own single cell patterns. There are a number of different versions of Braille:
•Grade 1, which consists of the 26 standard letters of the alphabet and punctuation. It is only used by people who are first starting to read Braille.
•Grade 2, which consists of the 26 standard letters of the alphabet, punctuation and contractions. The contractions are employed to save space because a Braille page cannot fit as much text as a standard printed page. Books, signs in public places, menus, and most other Braille materials are written in Grade 2 Braille.
•Grade 3, which is used mainly in personal letters, diaries, and notes, and also in literature to some extent. It is a kind of shorthand, with entire words shortened to a few letters.
Braille has been adapted to write many different languages, including Chinese, and is also used for musical and mathematical notation. Its invention has also lead to new ways to help people with disabilities, such as detectable warnings, which are also known as 'Braille for the feet'.
