Dictionary Check: lens

genus of small erect or climbing herbs with pinnate leaves and small inconspicuous white flowers and small flattened pods: lentils

a transparent optical device used to converge or diverge transmitted light and to form images

(metaphor) a channel through which something can be seen or understood

biconvex transparent body situated behind the iris in the eye; its role (along with the cornea) is to focus light on the retina

electronic equipment that uses a magnetic or electric field in order to focus a beam of electrons