1823-2023: the bicentennial of the Fresnel lens200 years ago, after several years of experiments, Augustin Fresnel (1788-1827) installed the first lenticular apparatus at the top of Cordouan lighthouse. His invention, the annular lens called the “Fresnel lens”, revolutionized maritime signaling. Fresnel, a physicist, engineer, architect, and visionary, drew heavily upon the theories of his predecessors by readapting them to improve the lighthouse illumination system.His work gave French engineering a global influence because most lighthouses worldwide are now equipped with Fresnel lenses.This exposition recounts the whole history of Augustin Fresnel’s invention, from its creation to its current use.This exposition is part of the commemoration of the bicentennial of the Fresnel lens, an event which was started by the General Secretariat for the sea in collaboration with the French lighthouse association and the association Les Petits Debrouillards. Graphic design by: Les Petits Debrouillards.