Zacharias Janssen is the Dutch spectacle maker who is widely credited as the inventor of the first compound microscope. Although many of the archives surrounding Janssen's invention have been lost, historians believe that Zacharias and his father Hans invented the first microscope at some point in the 1590s.
The earliest known example of a Janssen microscope is thought to have consisted of three draw tubes and a biconvex eyepiece. This microscope was created in 1595 and was capable of magnifying an image up to 10 times its actual size. The compound microscope was an important advancement over single lens magnification and led to many important discoveries.