The centre of the lens is called the optical centre C. In a ray diagram, a converging lens is drawn as a vertical line with outward facing arrows to indicate the shape of the lens. Point the lens ...

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 ...

Scientists have developed a new type of lens that creates multiple focal points, which could make for glasses or contacts that provide a clearer view over a range of distances. The secret?