/ lenz; NAmE / noun
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
—picture at binoculars , camera , frame , glass
—see also fisheye lens , telephoto lens , wide-angle lens , zoom lens
( informal ) = contact lens :
Have you got your lenses in?
( anatomy ) the transparent part of the eye, behind the pupil , that focuses light so that you can see clearly
—picture at eye
late 17th cent.: from Latin , lentil (because of the similarity in shape).