Lens of the human eye: The structure of the fetal (A) and adult (B) human lens, showing the major details of arrangement of the lens fibers. The anterior (a) and posterior (b) triradiate sutures are shown in the fetal lens. Fibers pass from the apex of an arm of one suture to the angle between two arms at the opposite pole, as shown in the colored segments. Intermediate fibers show the same reciprocal behavior. The suture pattern becomes much more complex as successive strata are added to the exterior of the growing lens, and the original arms of each triradiate suture show secondary and tertiary dichotomous branchings.
(By permission from Hogan MJ, Alvarado JA, Weddell JE 1971 Histology of the Human Eye. Philadelphia: WB Saunders.)