lens

Etymology

Borrowed from Latin lēns (“lentil”); Medieval Latin later taking on the sense of "lens"; a semantic loan from Arabic عَدْسَة (ʕadsa, “lentil; optic lens”).

noun

1. An object, usually made of glass, that focuses or defocuses the light that passes through it.
   Not long ago, it was difficult to produce photographs of tiny creatures with every part in focus. That’s because the lenses that are excellent at magnifying tiny subjects produce a narrow depth of field. 2013 July-August, Catherine Clabby, “Focus on Everything”, in American Scientist
2. A device which focuses or defocuses electron beams.
3. (geometry) A convex shape bounded by two circular arcs, joined at their endpoints, the corresponding concave shape being a lune.
4. (biology) A genus of the legume family; its bean.
5. (anatomy) The transparent crystalline structure in the eye.
   The single-imaging optic of the mammalian eye offers some distinct visual advantages. Such lenses can take in photons from a wide range of angles, increasing light sensitivity. They also have high spatial resolution, resolving incoming images in minute detail. 2013 July-August, Fenella Saunders, “Tiny Lenses See the Big Picture”, in American Scientist
6. (earth science) A body of rock, ice, or water shaped like a convex lens.
7. (programming) A construct used in statically-typed functional programming languages to access nested data structures.
8. (by extension, figurative) A way of looking, literally or figuratively, at something.
   If "the public looks at the condition of America's children largely through a negative lens," worries Child Trends[…], "it may be more difficult to […] promote child well-being." April 11 2004, Ann Hulbert, “Are the Kids All Right?”, in The New York Times Magazine, page 11
   No film should be revised based on the lenses we now are, either voluntarily, or being forced to peer through. 2023-04-26, Benjamin Lee, quoting Steven Spielberg, “Steven Spielberg: ‘No film should be revised’ based on modern sensitivity”, in The Guardian, →ISSN

verb

1. (transitive, cinematography) To film, shoot.
   It’s set in an anonymous, upper-middle-class suburb, lensed in the generic gunmetal gray that will one day appear as dated as the fuzzy outlines of ’80s direct-to-video horror movies. 2020-5-7, Katie Rife, “If you’re looking to jump in your seat, make a playdate with Z”, in The Onion AV Club
2. (geology) To become thinner towards the edges.