After losing his sight in a childhood accident, a young Frenchman invents a tool that will change the lives of blind people around the world.

Nicola Coughlan shines a light on extraordinary young people from across history. Join her for 12 stories of rebellion, risk and the radical power of youth.

This programme has been edited since first publication to remove the inaccurate suggestion that Charles Barbier’s raised dot code system was first developed for military use.

A BBC Studios Audio production for BBC Radio 4 and BBC Sounds.

Producer: Elaina Boateng Series Producer: Suniti Somaiya Executive Producer: Paul Smith Written by Alex von Tunzelmann Commissioning editor for Radio 4: Rhian Roberts