An aspheric lens, or sometimes known as an asphere, is a lens that’s not part of a sphere or cylinder and it can depart somewhat from a sphere. The more complex surface profile of an asphere not only reduces or eliminates spherical aberration but can also reduce other optical aberrations such as astigmatism. The result is a lens which creates sharper and clearer images. Aspheric surfaces are used in a variety of optical systems and are a powerful way of reducing the number of elements required.