Meaning of LENS in English
1》 a piece of glass or other transparent material with one or both sides curved for concentrating or dispersing light rays.
↘ Anatomy the transparent elastic structure behind the iris by which light is focused on to the retina of the eye.
↘short for contact ~ .
2》 the light-gathering device of a camera, containing a group of compound ~es.
3》 Physics an object or device which focuses or otherwise modifies a beam of radiation, sound, electrons, etc.
C17: from L., 'lentil' (because of the similarity in shape).
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004