Timeline of microscope technology * c. 700 BCE: The "Nimrud lens" of Assyrians manufacture, a rock crystal disk with a convex shape believed to be a burning or magnifying lens. * 13th century: The increase in use of lenses in eyeglasses probably led to the wide spread use of simple microscopes (single lens magnifying glasses) with limited magnification. * 1590: earliest date of a claimed Hans Martens/Zacharias Janssen invention of the compound microscope (claim made in 1655). * After 1609: Galileo Galilei is described as being able to close focus his telescope to view small objects close up and/or looking through the wrong end in reverse to magnify small objects. A telescope used in this fashion is the same as a compound microscope but historians debate whether Galileo was magnifying s