Lens

1. A ground or molded piece of glass, plastic, or other transparent material with opposite surfaces either or both of which are curved, by means of which light rays are refracted so that they converge or diverge to form an image. I have two lenses for use on my new camera.
2. A transparent, biconvex body of the eye between th iris and the vitreous humor that focuses light rays entering through the pupil to form an image on the retina. Cataract surgery is the removal of the natural lens, then an artificial intraocular lens implant is inserted.