lens
UK[lenz]US[lenz]
n
a curved piece of glass or plastic that makes things look larger, smaller, or clearer when you look through it.
n
a part of the eye, behind the pupil, that focuses light so that you can see clearly.
Etymology
the english word 'lens' is a direct borrowing from latin, where 'lens' specifically meant 'lentil'. the term was adopted into scientific use in the 17th century by scholars such as kepler to describe the shape of glass pieces used in optical instruments, which resembled the flat, double-convex form of the lentil seed. this metaphorical naming based on physical resemblance is a classic example of how common objects provide vocabulary for scientific concepts. from this concrete origin, the meaning expanded to encompass any piece of transparent material with curved surfaces for focusing light, including the natural lens in the eye.
Analysis
this word is a simplex loanword. it is derived from the latin word 'lens', meaning 'lentil', due to the similarity in shape between a double-convex lens and a lentil seed.
Examples
i need to clean the lens of my camera.
the surgeon removed the clouded lens during the cataract operation.
he adjusted the focus by rotating the lens slightly.