Room VI presents a range of apparatuses and basic components (such as prisms, lenses, and diaphragms) for the study of optics—a science that underwent a radical transformation in the seventeenth century thanks to the fundamental contributions of Kepler, Descartes, and Newton. There are many prisms, used to break down white light into a polychromatic spectrum, as well as parts of optical benches for performing a wide variety of experiments. Of particular significance is the microscope designed by the Duc de Chaulnes, the only surviving example fully consistent with the description published by its famous inventor. One of the consequences of the spread of an optical science firmly based on geometrical principles was the dissemination of optical toys. By exploiting the laws of perspective and the properties of lenses, mirrors, and prisms, these devices produced effects that astonished the public. Among such effects, anamorphoses were particularly popular in the second half of the seventeenth century. Also on view in Room VI is a rare and beautiful eighteenth-century lathe for working lenses.