Researched
Braille
Louis Braille, aged 15, devises a six-dot tactile alphabet (1824) that blind people can read and write.
Open in the interactive tree →He adapted Barbier's military 'night writing' into a compact cell of six dots; the system was published in 1829 and adopted in schools for the blind. Braille remains the main literacy tool for blind readers, now supported by screen readers and refreshable displays.