a lens that focuses the image in a camera

Plural form of focus, verb_ Third-person singular simple present indicative form of focus

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, A piece of transparent substance bounded by two curved surfaces (usually spherical), or by a curved surface and a plane, An object, usually made of glass, that focuses or defocuses the light that passes through it, transitive verb_ To bend or distort (light, for example) by means of a lens, especially a gravitational field, Informal To make a photograph or movie of, verb_ transitive To film, shoot, geology To become thinner towards the edges

a convex lens that focuses the rays of the sun; used to start a fire