When Louis was 19, Dr. Pignier hired him to be an apprentice teacher at the Institute at a salary of 180 francs per year. Louis taught several classes including algebra, grammar, and geometry, to both sighted and blind students. With the appointment to apprentice teacher, Louis moved out of a dormitory and was provided his own room.

In 1833 at the age of 24, Louis and two other blind friends including his best friend Gabriel Gauthier, were made full-fledged teachers. For his work Louis received a salary of 300 francs per year. After 1835, Louis only provided instruction to blind students. With his salary he was able to buy himself a piano, lend money to friends who were in need, and pay people to help write books using his code. In 1834, the Exposition of Industry was held in Paris, and Louis was permitted to exhibit his code and demonstrated it to attendees.