Fizeau and Foucault were schoolfriends, both abandoning medical studies for physics. Donné had been his professor at medical school; together they produced a book on microscopic anatomy that pioneered the use of photography in printed publications. He worked together with Regnault on binocular vision, and met Thomson in Regnault’s laboratory. Arago, whose eyesight was failing, suggested the work Foucault and Fizeau did on the velocity of light; the two also produced the first photo of the sun’s surface. Thomson was working in Regnault’s laboratory when Foucault met him.