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Light rays converge when passing through a biconvex lens (top) and diverge when passing through a biconcave lens (bottom).f indicates the focus.
n. pl. lens·es
1. A ground or molded piece of glass, plastic, or other transparent material with opposite surfaces either or both of which are curved, by means of which light rays are refracted so that they converge or diverge to form an image.
2. A combination of two or more such pieces, sometimes with other optical devices such as prisms, used to form an image for viewing or photographing. Also called compound lens.
3. A thin piece of glass or plastic, as on a pair of sunglasses, that transmits light without refraction.
4. A device or phenomenon (such as a gravitational field) that causes light or other radiation to converge or diverge by an action analogous to that of a lens.
a. A transparent, biconvex structure in the eye of a vertebrate or cephalopod that is located between the iris and the vitreous humor and focuses light rays entering through the pupil to form an image on the retina.
b. A similar structure in many invertebrates.
tr.v. lensed, lens·ing, lens·es
1. Informal To make a photograph or movie of.
2. To bend or distort (light, for example) by means of a lens, especially a gravitational field.
[New Latin lēns, from Latin, lentil (from the shape of a double convex lens).]
materials which colour and diffuse light