The oldest history of microscope goes to 1590s, when two Dutch spectacle makers, Zacharias Jansen and his father Hans Jansen, started some tests with lenses. They combined several lenses and put inside a tube and boom, they made the discovery. They saw an object at the end of the tube can bee seen way larger than it was supposed to be. The very fist microscope was invented this way had a magnification about 9x. The achieved image was much larger than that by a magnifying glass but ofcourse it was blurry.
Joseph Jackson Lister (1786-1869) English physicist and optician who made important improvements to the microscope. On the table beside him, his improved microscope (1828) which had a perfectly achromatic combination of lenses. Photo by University History Archive/Getty Images. Source.
Antonio Luna (1866-1899), Filipino General, got Doctorate in 1893 with research on Malaria pathology, at the Institut Pasteur in Paris, France, 1890. Source.
Albert Calmette, French Bacteriologist and founder of the Pasteur bacteriological Institute at Saigon, in the laboratory in the institute in Lille (1891). He also founded and directed the Pasteur Institute in Lille (1896-1919). With Camille Guerin, he developed vaccination against tuberculosis for children. Source.
USSR (now Russian) school, biology lesson in Leningrad (now St Petersburg), 1950s. Source.