1690s, "glass to regulate light rays," from Latin lens (genitive lentis) "lentil," on analogy of the double-convex shape. See lentil. Of the eye from 1719.
In the vernacular of the photographer, anyone crowding to the front of a group, staring into the lens, or otherwise attracting attention to himself is known as a "lens louse." ["American Photography," vol. 40, 1946; the term dates from 1915]
lens (lěnz)
n. pl. lens·es
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.
A transparent, biconvex body of the eye between the iris and the vitreous humor that focuses light rays entering through the pupil to form an image on the retina.
A piece of transparent material, such as glass, that forms an image from the rays of light passing through it. (See focal length, refraction, and telescope.)
industrial town, Pas-de-Calais departement, Nord-Pas-de-Calais region, 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