In 1590 Zacharias and Hans Jensen invented the first compound microscope. It is used to see samples of things the naked eye can't see.
Zachariah Jansen was the inventor of the first ever microscope. the microscope was shape like a tube but with two lens on the ends of it. He was important to the cell theory because they're wouldn't be a microscope without him.
The three parts of the cell theory are that all living things are composed of cells. Cells are the basic units of structure and function in all living things, and all cells are produced from other cells.
In 1635, Robert Hooke was an architect who invented another microscope. His microscope was different because his had light from a flame. He was important to the cell theory because he discovered honey-comb like structure that he called cells.
In 1674, Anton Van Lee Leeuwenhoek invented a different microscope. His microscope was different because he used one little lens. Anton was important to the cell theory because he was the first scientist to closely observe cells under a microscope.
In 1838 Matthlas Schleden created his own type of microscope. He was important to the cell theory because he discovered that all plant tissues are composed of cells.
Theodor Schwann created his own microscope. He was important to the cells theory like the plants that all animals were composed of cells. He also was a big help to figuring out the cell theory.
Rudolph Virchow also created his own microscope. He was important to the cell theory because he added the third part to the cell theory. He also discovered that healthy and diseased cells derive from the healthy cells of normal tissue.