Microscope 

The Microscope, an invention created by two eyeglass makers;  Hans Lippershey and  Zacharias Janssen, is what we currently use to enlarge subjects that are either difficult or impossible to see with the naked eye. There are Three  different lenses; One large, one meduim and one small. underneath these three lenses, you input a  clean glass slide which has,attatched to it,  whatever subject you  are trying to inspect. You place the little metal clips over the top of the slide to keep it still. You then look into the scope at the top, and adjust the lens to the one you want.