The transparent structure lying just behind the pupil of the eye that refracts light rays.
A transparent colorless biconvex structure in the eye, enclosed in a capsule, and held in place just behind the pupil by the suspensory ligament. It consists principally of lens fibers that at the periphery are soft, forming the cortex lentis, and in the center of harder consistency, forming the nucleus lentis. Beneath the capsule on the anterior surface is a thin layer of cells, the lens epithelium. The shape is changed by the ciliary muscle to focus light rays on the retina.
The lens of the eye located behind the pupil, which is termed a cataract when it becomes cloudy and milky in appearance.