Lens Lens (l[e^]nz), n.; pl. {Lenses} (-[e^]z). [L. lens a lentil. So named from the resemblance in shape of a double convex lens to the seed of a lentil. Cf. {Lentil}.] (Opt.) A piece of glass, or other transparent substance, ground with two opposite regular surfaces, either both curved, or one curved and the other plane, and commonly used, either singly or combined, in optical instruments, for changing the direction of rays of light, and thus magnifying objects, or otherwise modifying vision. In practice, the curved surfaces are usually spherical, though rarely cylindrical, or of some other figure. [1913 Webster] Lenses [1913 Webster]

Note: Of spherical lenses, there are six varieties, as shown in section in the figures herewith given: viz., a plano-concave; b double-concave; c plano-convex; d double-convex; e converging concavo-convex, or converging meniscus; f diverging concavo-convex, or diverging meniscus. [1913 Webster]

{Crossed lens} (Opt.), a double-convex lens with one radius equal to six times the other.

{Crystalline lens}. (Anat.) See {Eye}.

{Fresnel lens} (Opt.), a compound lens formed by placing around a central convex lens rings of glass so curved as to have the same focus; used, especially in lighthouses, for concentrating light in a particular direction; -- so called from the inventor.

{Multiplying lens} or {Multiplying glass} (Opt.), a lens one side of which is plane and the other convex, but made up of a number of plane faces inclined to one another, each of which presents a separate image of the object viewed through it, so that the object is, as it were, multiplied.

{Polyzonal lens}. See {Polyzonal}. [1913 Webster]

The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Lens — can refer to: NOTOC In optics*Lens (optics), an optical element which converges or diverges light **Lens (anatomy), a part of the eye **Corrective lens for correction of human vision ***Contact lens, placed on the cornea of the eye **Photographic …   Wikipedia

  • LENS — La ville de Lens comptait en 1990 35 278 habitants et celle de Liévin 34 012. Il s’agit en réalité d’un ensemble de communes qui englobent le quart du bassin minier. Sur le site de passage entre la France et les bas pays, dominée par les hauteurs …   Encyclopédie Universelle

  • lens — [lenz] n [Date: 1600 1700; : Latin; Origin: lentil ; because of its shape] 1.) the part of a camera through which the light travels before it reaches the film ▪ a standard 50mm lens 2.) a piece of curved glass or plastic which makes things look… …   Dictionary of contemporary English

  • lens — (n.) 1690s, glass to regulate light rays, from L. lens (gen. lentis) lentil, on analogy of the double convex shape. See LENTIL (Cf. lentil). Of the eye from 1719. In the vernacular of the photographer, anyone crowding to the front of a group,… …   Etymology dictionary

  • lens — [ lenz ] noun count * 1. ) a thin piece of curved glass or plastic that makes things seem smaller, bigger, or clearer: eyeglasses with thick lenses a ) a piece of equipment that is part of a camera: a camera with a telescopic lens 2. ) the part… …   Usage of the words and phrases in modern English

  • Lens —   [lãs], Stadt im Département Pas de Calais, im Kohlenrevier Nordwestfrankreichs, 38 m über dem Meeresspiegel, 35 000 Einwohner; Steinkohlenbergbau, Kokerei, Stahl und Konfektionsindustrie.   Geschichte:   Lens wurde im Ersten Weltkrieg stark… …   Universal-Lexikon

  • LENS — Graece φακῆ, tenuiorum et Philosophorum cibus, Cynicorum praesertim, olim fuit, cuius encomium vide apud Athen. l. 4. c. 18. Sed et edulio eius tantopere in sacris Esavus legitur gavisus, ut iure primogentiurae illud redimere profanus homo non… …   Hofmann J. Lexicon universale

  • lens — [lenz] n. [L, lentil: from the resemblance to the shape of a lentil] 1. a) a piece of glass, or other transparent substance, with two curved surfaces, or one plane and one curved, regularly bringing together or spreading rays of light passing… …   English World dictionary

  • Lens — (spr. langß), Stadt im franz. Dep. Pas de Calais, am Souchez, (1901) 24.370 E.; Industrie …   Kleines Konversations-Lexikon

  • lens — ► NOUN 1) a piece of transparent material with one or both sides curved for concentrating or dispersing light rays. 2) the light gathering device of a camera, containing a group of compound lenses. 3) Anatomy the transparent elastic structure… …   English terms dictionary

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