What is a microscope? How the microscope has evolved over three hundred and fifty years

Abstract The microscope is named from the Greek mikrós (small) and skopeîn (to see). The first light microscopes were described over three hundred and fifty years ago, building on the development of lenses for the telescope. The publication of Micrographia in 1665 popularised the microscope and yet its technological development only really took off in the 1800s in parallel with many other technological developments of the time. Key to building microscopes reproducibly was the theoretical understanding of how the image is formed in the microscope, developed by Ernst Abbe in the 1880s as part of his collaboration with Carl Zeiss. That eventually led to the standardisation of light microscopes with the help of the Royal Microscopical Society. The electron microscope was then invented in the 1930s, building on principles already uncovered for light microscopy. The microscope has continued to evolve to help us to see even smaller and smaller objects across the physical and life sciences, and it is a key tool for many scientists. This overview briefly summarises the development of the microscope from its early origins up to the present day.