Zacharias Janssen was a Dutch spectacle-maker from Middelburg associated with the invention of the first optical telescope.
Anton von Leeuwenhoek
Antonie Philips van Leeuwenhoek was a Dutch tradesman and scientist. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist
Robert Hooke FRS was an English natural philosopher, architect and polymat
Matthias Jakob Schleiden was a German botanist and co-founder of the cell theory, along with Theodor Schwann and Rudolf Virchow
Theodor Schwann was a German physiologist. His many contributions to biology include the development of cell theory, the discovery of Schwann cells in the peripheral nervous system,
Carl Zeiss was a German maker of optical instruments best known for the company he founded, Carl Zeiss Jena. Zeiss made contributions to lens manufacturing that have aided the modern production of lenses
Rudolf Ludwig Carl Virchow was a German physician, anthropologist, pathologist, prehistorian, biologist, writer, editor, and politician, known for his advancement of public health.
Ernst Karl Abbe was a German physicist, optical scientist, entrepreneur, and social reformer. Together with Otto Schott and Carl Zeiss, he laid the foundation of modern optics. Abbe developed numerous optical instruments.