Which instrument, invented earlier but refined and widely used in the 18th century, made it possible to observe the microscopic world?

Fact

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The first compound microscopes probably appeared in the late 16th or early 17th century. In the 17th century, Robert Hooke published detailed microscopic observations in "Micrographia", while Antonie van Leeuwenhoek notably observed microorganisms with high-performance single-lens instruments. In the 18th century, microscopes continued to be perfected and used in the study of life and materials. They thus contributed to the scientific progress associated with the Enlightenment, but they were not invented there. The question must distinguish the use and improvement of an instrument from its historical appearance.