Digital fundus photography produces digital images of back of the eye. It is a highly specialized form of medical imaging, it can't be done with an ordinary camera. It requires a customized camera that is mounted to a microscope with intricate lenses and mirrors. These high-powered lenses are designed so the photographer can visualize the back of the eye by focusing light through the cornea, pupil and lens. These photographs are used for comparison, documentation, and sometimes to diagnose certain eye conditions.