1 a curved piece of glass or plastic that makes things look larger, smaller or clearer when you look through it:
a pair of glasses with tinted lenses * a camera with an adjustable lens * a lens cap / cover
seealsoFISHEYELENS, TELEPHOTOLENS, WIDE-ANGLELENS, ZOOMLENS
2 (informal) = CONTACTLENS:
Have you got your lenses in?
3 (anatomy) the transparent part of the eye, behind the PUPIL, that FOCUSES light so that you can see clearly
