Eye lens fibres. Coloured scanning electron micrograph (SEM) of a freeze-fracture of fibres from the lens of an eye. Lens cells lack a nuclei, and the main constituent of the cells is the protein crystallin. Tightly packed layers of lens fibres (as seen here) are referred to as laminae. The lens fibres are linked together via gap junctions (one seen here) and interdigitations of the cells. The transparency of the lens is thought to arise from the regular arrangement of these cells. Magnification: x2000 when printed at 10 centimetres wide.