Lens is a transparent glass which is bounded by two spherical surfaces. The light rays are refracted after passing through the lens. It is of two types, convex lens and concave lens.

In a telephoto lens, the magnification of the subject is achieved through a combination of convex and concave lenses. In its simplest form, a convex lens on the outside converges light.

A plano-convex lens is compose of a plane and convex surfaces, has a positive focal length.It is used for the changing between point light source and parallel beam.It is mean when the light through ...

Lenses are used in cameras, telescopes, binoculars, microscopes and corrective glasses. A lens can be converging (convex) or diverging (concave).

The case itself is made out of polymers which, depending on the voltage change the lens' to be more convex or concave, allowing it to "zoom in or out," like changing the focal length on a camera.

Source: NOVA: "Galileo's Battle for the Heavens" This resource was adapted from NOVA: "Galileo's Battle for the Heavens." The first telescopes, invented in 1608, consisted of two simple concave ...

The properties of concave and convex lenses were first described around the year 1000, although magnifiers in the form of lens-shaped crystals or glass may have been used much earlier.