An optical lens is an optical device, which has perfect or approximate axial symmetry, and will reflect and transmit light. A simple optical lens is a lens consisting of a singular optical element, and a compound optical lens, consists of an array of single lenses with a common axis. This type of optical lens allows the correction of more optical aberrations, than is possible with a single lens. A manufactured optical lens is typically made of glass or even transparent plastic. There are various types of optical lens, and these are classified by the curvature of the two optical surfaces, for instance; an optical lens with two concave surfaces is known as a biconcave lens. Other optical lens names are Biconvex, Plano convex, Positive-meniscus, Negative-meniscus and Plano-concave.