Language & WorldHow it works
How six dots make a whole alphabet.
A braille cell has six dots; each is raised or not, giving 64 combinations including the space. Letters a to j use only the upper four dots and, with a prefix sign, double as digits 1 to 0. Louis Braille designed it in 1824, aged 15, after Charles Barbier's night writing, whose 12-dot cells were too big for a fingertip.
Useful: Run a finger over the dots on a medicine box: the name is written there in braille.
Source: en.wikipedia.org