Louis Braille’s raised-dot alphabet system of reading and writing, known simply as braille, is now used internationally. The reader runs a finger over impressions in order to interpret them.

A stylus, in this context, is a sharp pin held like a pencil which can be used to create impressions in paper. Braille developed his system using a stylus. Modern inventions, like the braille typewriter, now allow Braille’s alphabet to be produced mechanically—rather than with a stylus.

Captain Charles Barbier developed this method of communication. The system used dots and dashes to represent sounds and phrases, which could be combined to create words and sentences. Sonography, which Braille found promising but onerous, inspired him to create his own system of reading and writing using raised dots.