Lens

The internal optical component of the eye responsible for focusing; also called the crystalline lens. It is situated behind the iris and is suspended on delicate fibres from the ciliary body. The lens is elastic, transparent, and slightly less convex on the front surface than on the back. Changing its curvature alters the focus so that near or distant objects can be seen sharply (see accommodation). Opacification of the lens is called cataract. (See also lens dislocation.)