Evidence of zonular stress lines on human crystalline lens

The lens is an extremely planned system of focused cells which constitutes an important element of optical arrangement of the eye and fulfills the important functions of altering the refractive index of light entering the eye to focus on the retina.1,2 The transparency of lens is due to the shape, array, internal structure, and biochemistry of the lens cells or lens fibre.1 The lens is held in place by composite three dimensional systems of radially arranged zonules called zonules of Zinn or the suspensory ligament of the lens.1 These fragile fibres are attached to the lens capsule 2mm anterior and 1mm posterior to the equator and arise from the region of pars plana ciliary epithelium and pass forward closely related to the lateral surfaces of ciliary processes.1 The fibrous zonules blend with basal lamina of the lens capsule. The anterior and posterior zonules place in obliquely into superficial 1-2μm of preand post-equatorial lens capsule, while equatorial zonules insert at right angles.1–3 We present the documentation of zonular stress lines (ZSLs) for the first time in the scientific literature on the transparent crystalline lens from three enucleated eyeballs. These stress lines are the evidence of the zonules to take part in accommodation and also arbitrate accommodative movements. Although some believed that there are two types of zonules, first being ‘main zonules’ and other the ‘tension zonules’, the later being placed under tension during accommodation but there were no morphological different stress lines on the surface of lens in so called two varieties of zonules.1–3