Louis Braille, himself a visually challenged person, developed a system for visually challenged persons and published it in 1821.
Braille system has 63 dot patterns or characters. Each character represents a letter, a combination of letters, a common word or a grammatical sign. Dots are arranged in cells of two vertical rows of three dots each.
Patterns of dots to represent some English letter.
These patterns when embossed on Braille sheets help visually challenged persons to recognise words by touching. To make them easier to
touch, the dots are raised slightly.