Figure 2-29 Organization of the lens. At areas where lens cells converge and meet, sutures are formed. A, Cutaway view of the adult lens showing an embryonic lens inside. The embryonal nucleus has a Y-shaped suture at both the anterior and posterior poles; in the adult lens cortex, the organization of the sutures is more complex. At the equator, the lens epithelium can divide, and the cells become highly elongated and ribbonlike, sending processes anteriorly and posteriorly. As new lens cells are formed, older cells come to lie in the deeper parts of the cortex. B, Cross section and corresponding surface view showing the difference in lens fibers at the anterior (A), intermediate (B), and equatorial (C) zones. The lens capsule, or basement membrane of the lens epithelium (d), is shown in relation to the zonular fibers (f) and their attachment to the lens (g). C, The diagram shows a closer view of lens sutures. D and E, Optical sections of the lens of a young adult human (25-year-old woman) demonstrated by Scheimpflug photography. The cornea is to the right. The lens is in the nonaccommodative state in part D. The lens is shown during accommodation in part E. Note that the anterior radius of curvature is shortened in the latter case.