—lensless, adj. —lenslike, adj./lenz/, n., pl. lenses, v.n.1. a piece of transparent substance, usually glass, having two opposite surfaces either both curved or one curved and one plane, used in an optical device in changing the convergence of light rays, as for magnification, or in correcting defects of vision.2. a combination of such pieces.3. some analogous device, as for affecting sound waves, electromagnetic radiation, or streams of electrons.4. Anat. See crystalline lens.5. Geol. a body of rock or ore that is thick in the middle and thinner toward the edges, similar in shape to a biconvex lens.v.t.6. Motion Pictures. to film (a motion picture).[1685-95; < NL, special use of L lens a lentil (from its shape); see LENTIL]
* * *Piece of glass or other transparent substance that is used to form an image of an object by converging or diverging rays of light from the object.Because of the curvature of its surface, different rays of light are refracted (see refraction) through different angles. A convex lens causes rays to converge on a single point, the focal point. A concave lens causes rays to diverge as though they are coming from a focal point. Both types cause the rays to form a visual image of the object. The image may be realinverted and photographable or visible on a screenor it may be virtualerect and visible only by looking through the lens.
* * *▪ Franceindustrial town, Pas-de-Calais département, Nord-Pas-de-Calais région, northern France, southwest of Lille. It was the chief urban centre of the Pas-de-Calais coal basin. Since the demise of coal mining in the 1980s, a wide range of new industries and services has been developed in Lens. These include companies manufacturing wires and cables, paper, metals, glass, frozen foods, and chemicals, as well as firms specializing in packaging and transport. Lens is also a commercial and administrative centre, and it is the site of a branch of the University of Artois. The town, which was completely destroyed in World War I, was damaged again in World War II. Pop. (1999) town, 36,206; (2004 est.) 35,200.
* * *