Lens (surname)
Lens is a surname. Notable people with the surname include:
Lens
Lens may refer to:
Optics
- Lens (anatomy), a part of the eye
- Corrective lens for correction of human vision
- Contact lens, placed on the cornea of the eye
- Camera lens, a lens designed for use on a camera
- Contact lens, placed on the cornea of the eye
Other radiation focus and forces
Places
Lens (optics)
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.
History
The word lens comes from the Latin name of the lentil, because a double-convex lens is lentil-shaped. The genus of the lentil plant is Lens, and the most commonly eaten species is Lens culinaris. The lentil plant also gives its name to a geometric figure.
The variant spelling lense is sometimes seen. While it is listed as an alternative spelling in some dictionaries, most mainstream dictionaries do not list it as acceptable.
Lens (hydrology)
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.
