Zacharias Janssen was a Dutch spectacle-maker of Middelburg.
Hans Janssen and his son Zacharias Janssen, Dutch spectacle-makers, are frequently cited as having invented the first compound microscope in 1590, but there is a good deal of dispute. They may not have. Zacharias Janssen was the one who actually made the claim, and in the middle of the 1600's. A number of historians, however, agree that it is imporbable that 1590 is correct. There is a good deal of evidence that Zacharias Janssen was born somewhere around 1590.