'See for yourself!' was the clarion call of the 1600s. Natural philosophers threw off the yoke of ancient authority, peered at nature with microscopes and telescopes, and ignited the Scientific Revolution. Artists investigated nature with lenses and created paintings filled with realistic effects of light and shadow. The hub of this optical innovation was the small Dutch city of Delft. Here Johannes Vermeer's experiments with lenses and a camera obscura taught him how we see under different conditions of light and helped him create the most luminous works of art ever beheld. Meanwhile, his neighbor Antoni van Leeuwenhoek's work with microscopes revealed a previously unimagined realm of minuscule creatures. The result was a transformation in both art and science that revolutionized how we see the world today.