Anton van Leeuwenhoek (1632-1723) was the first person to make and use a real microscope. He was able to utilize 550 different lenses in order to produce a lens tube that could view objects that were one millionth of a meter, or 270X magnification.
Without all of the progress that has been made in the field of microscopy since Leeuwenhoek, we wouldn't even know that these tiny organisms unable to be seen by the naked eye even exist. Advancements in microscopy continue to be made every day to help us better understand microorganisms and how they affect our everyday lives.