Braille is a tactile method of reading and writing for blind people developed by Louis Braille (1809-1852), a blind Frenchman. The braille system uses six raised dots in a systematic arrangement with two columns of three dots, known as a braille cell. By convention, the dots in the left column are numbered 1, 2 and 3 from top to bottom and the dots in the right column are numbered 4, 5 and 6 from top to bottom.
The six dots of the braille cell are configured in 64 possible combinations (including the space which has no dots present). The 63 braille characters with dots are grouped in a table of seven lines. This table is used to establish "braille order" for listing braille signs.
Line 1 is formed with characters in the upper part of the cell, using dots 1, 2, 4 and 5.
Line 2 adds dot 3 to each of the characters in Line 1.
Line 3 adds dots 3 and 6 to each of the characters in Line 1.
Line 4 adds dot 6 to each of the characters in Line 1.
Line 5 repeats the dot configurations of Line 1 in the lower part of the cell, using dots 2, 3, 5 and 6.
Line 6 is formed with characters using dots 3, 4, 5 and 6.
Line 7 is formed with characters in the right column of the cell, using dots 4, 5 and 6.
An individual may write braille by hand either using a slate and stylus to push dots out from the back of the paper working from right to left or using a mechanical device called a brailler. A person may also use an embosser to reproduce an electronic braille file. These methods all produce embossed braille on hardcopy paper.
A person may read an electronic braille file by using a refreshable braille display attached to his/her computer. This employs pins which raise and lower to form the braille characters.
Originally developed to represent the French language, braille has been adapted for English and many other languages.
Braille is used to represent all subject matter, including literature, mathematics, science and technology. Louis Braille developed the system which is used worldwide today for representing music.
Unified English Braille (UEB) is a system of English braille which represents all subjects except music.
The purpose of UEB is to allow the reader to understand without ambiguity what symbols are being expressed by a given braille text.
The primary transcribing rule is to produce braille that, when read, yields exactly the original print text (apart from purely ornamental aspects).
A print symbol has one braille equivalent in UEB. Use the braille sign for that print symbol regardless of the subject area.