Claude Mydorge was a French mathematician who trained as a lawyer but was wealthy enough that he didn't have to work for a living. He was interested in mathematical puzzles and his book Examen du livre des récréations mathématiques (1630) formed the basis for later works such as that by Denis Henrion (1659). Mydorge edited Récréations Mathématique and left an unpublished manuscript of over 1,000 geometric problems and their solutions. He was also interested in optics and made a large number of instruments for his close friend René Descartes; the two shared a strong interest in explaining vision and the instruments and lenses were designed to help test their theories.