Optics is concerned with the production, propagation and manipulation of light, the changes it undergoes and produces, and other closely related phenomena. Physical optics deals with the nature and properties of light while geometrical optics deals with the formation of images by mirrors, lenses, and other devices that use light. The study of optics has led to the development of devices such as eyeglasses and contact lenses, telescopes, microscopes, cameras, binoculars, lasers, and optical fibers.