What is "lens"

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

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.

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.

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.\n\nIn 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]

n. An object, usually made of glass, that focuses or defocuses the light that passes through it. vb. 1 (context transitive English) To film, shoot. 2 (context geology English) To become thinner towards the edges.

1. n. a transparent optical device used to converge or diverge transmitted light and to form images [syn: lense, lens system]

2. genus of small erect or climbing herbs with pinnate leaves and small inconspicuous white flowers and small flattened pods: lentils [syn: genus Lens]

3. (metaphor) a channel through which something can be seen or understood; "the writer is the lens through which history can be seen"

4. biconvex transparent body situated behind the iris in the eye; it focuses light waves on the retina [syn: crystalline lens]

5. electronic equipment that uses a magnetic or electric field in order to focus a beam of electrons [syn: electron lens]

A lens is a transmissive optical device that affects the focus of a light beam through refraction. A simple lens consists of a single piece of material, while a compound lens consists of several simple lenses (elements), usually along a common axis. Lenses are made from transparent materials such as glass, ground and polished to a desired shape. A lens can focus light to form an image, unlike a prism, which refracts light without focusing. Devices that similarly refract radiation other than visible light are also called lenses, such as microwave lenses or acoustic lenses.

The lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina. This adjustment of the lens is known as accommodation (see also below). Accommodation is similar to the focusing of a photographic camera via movement of its lenses. The lens is more flat on its anterior side than on its posterior side.

The lens is also known as the aquula (Latin, a little stream, dim. of aqua, water) or crystalline lens. In humans, the refractive power of the lens in its natural environment is approximately 18 dioptres, roughly one-third of the eye's total power.

1. Redirect Lens, Pas-de-Calais

Lens is a genus of the legume family mostly known for its edible seeds, which are referred to as lentils. Lens contains four species of small, erect or climbing herbs with pinnate leaves, small inconspicuous white flowers, and small flattened pods. The lentil most commonly eaten is the seed of Lens culinaris.

In 2-dimensional geometry, a lens is a convex set bounded by two circular arcs joined to each other at their endpoints. In order for this shape to be convex, both arcs must bow outwards (convex-convex). This shape can be formed as the intersection of two circular disks. It can also be formed as the union of two circular segments (regions between the chord of a circle and the circle itself), joined along a common chord.

In geology a lens is a body of ore or rock or a deposit that is thick in the middle and thin at the edges, resembling a convex lens in cross-section. Adjective: "lenticular".

A lens can also refer to an irregular shaped formation consisting of a porous, permeable sedimentary deposit surrounded by impermeable rock.

Category:Petrology Category:Sedimentology

In hydrology a lens is a convex layer of fresh groundwater that floats on top of denser saltwater. It arises when rainwater seeps down through a soil surface and then gathers over a layer of seawater at or down to about five feet below sealevel. Freshwater lenses are often found on small coral or limestone islands and atolls, where wells dug into them may be the only natural source of potable water.

Ghyben-Herzberg lenses are a simple model of the process.

"Lens" is a song by Canadian-American recording artist Alanis Morissette, released as the second single from her eighth studio album, Havoc and Bright Lights. The song was written by Morissette and Guy Sigsworth, and produced by Sigsworth and Joe Chiccarelli. The song was played at most shows of Guardian Angel Tour.

Lens is a surname. Notable people with the surname include:

• Louis Lens, Flemish rose breeder
• Nicholas Lens, Belgian composer
• Josef Lense, physicist
• Jeremain Lens, Dutch-Surinamese footballer

Lens is a psychological thriller and a hostage drama written and directed by Jayaprakash Radhakrishnan. Dealing extensively with the lust for voyeurism in the digital world and its consequences, the movie goes beyond the banal bifurcation of the hero and the nemesis. Starring Anandsami and Jayaprakash himself as the lead, the movie unfolds as an edge of the seat thriller which keeps you guessing till the last minute.

Lens has been screened in several film festivals including Chennai International Film Festival, Pune International Film Festival, Bengaluru International Film Festival and Bioscope International Film Festival in Delhi.

The film has received much critical acclaim and appreciation. Malayalam Director, Vineeth Srinivasan said "There are so many things i wanted to say about this film.. Infact, if the movie was released already, i would have written in detail.. For now, i' ll just say this.. This film needs to be seen by today's internet savvy generation. It's relevant, it's gritty, it's honest and it haunts.. I hope many people take the effort to watch this film."