Concave lens
From Biocrawler, the free encyclopedia.
A concave lens is a lens with inward-curving (concave) surfaces: the ends are wide, the middle is small. Light passing through a concave lens is diverged. Concave lenses can be used in telescopes, microscopes, and eyeglasses. In glasses, they are used to compensate for myopia (nearsightedness). A convex lens produces a virtual image.
Nicholas of Cusa is believed to have been the first to discover the benefits of concave lens for the treatment of myopia in 1451.
See also: convex lens
