# lens

Pronunciation: say "LENZ" /lɛnz/

## Noun

1. A usually glass object that focuses or spreads out the light that passes through it.
   - Simple: A clear piece of glass or plastic that bends light to make things look bigger, smaller, or sharper.
   - _The photographer swapped in a wide-angle lens for the landscape shot._
   - _Each lens in the telescope bends light to bring distant stars into focus._
2. The transparent crystalline structure inside the eye that focuses light onto the retina.
   - Simple: The clear, curved part inside the eye that focuses light onto the back of the eye.
   - _Surgeons removed the clouded lens and replaced it with an artificial implant._
   - _Tiny muscles reshape the lens so the eye can focus on nearby objects._
3. A particular way of looking at or interpreting something, whether literally or figuratively.
   - Simple: A particular point of view used to look at or judge something.
   - _Historians often view past events through the lens of their own era's values._
   - _Viewed through an economic lens, the policy looks very different._
4. A device that focuses or spreads out beams of electrons, much as a glass lens does with light.
   - Simple: A device that uses magnetic or electric fields to focus or spread out a beam of electrons.
   - _An electromagnetic lens bends the electron beam toward a fine focal point._
   - _Engineers aligned each lens to sharpen the image in the electron microscope._
5. A body of rock, ice, or water shaped like a convex lens, thicker at the center than at the edges.
   - Simple: A mass of rock, ice, or water shaped like a curved disk that is thicker in the middle.
   - _Geologists mapped a lens of gravel pinching out against the bedrock._
   - _Beneath the island, a lens of fresh groundwater sits above denser seawater._
7. A convex shape bounded by two circular arcs that meet at their endpoints; the matching concave shape is called a lune.
   - Simple: A pointed oval shape made by two curved lines that meet at both ends, like the space where two circles cross.
   - _The overlap of the two disks forms a lens with two curved sides._
   - _She calculated the area of the lens formed by two intersecting circles._
8. A construct in statically typed functional programming languages used to access and update nested data structures.
   - Simple: A programming tool that lets code reach and change values stored deep inside other values.
   - _She wrote a lens to update a single field in a deeply nested record._
   - _Composing one lens with another lets you reach values several layers down._
9. A genus of the legume family, or the small lens-shaped bean it produces.
   - Simple: A group of small legume plants, or the round, flat bean they produce.
   - _The cultivated lens has fed people across the Middle East for thousands of years._
   - _Botanists place the lens among the legumes, alongside peas and beans._

## Verb

6. To film or shoot something with a camera.
   - Simple: To film or record something with a camera.
   - _The director chose to lens the chase scene at dawn._
   - _A veteran cinematographer lensed the film's hardest scenes._
10. To gradually become thinner toward the edges.
   - Simple: To grow gradually thinner toward the edges, like a layer that slowly fades out.
   - _Geologists noted how the sandstone beds lens toward the basin margin._
   - _The volcanic ash deposits lens out and vanish a few miles east._

## Origin

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

Source: DictionaryAI, https://dictionaryai.com/define/lens (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).