Foetal lens. Light micrograph of a section through the lens from the eye of a developing foetus. In the developing foetal lens the surface epithelial cells (top) multiply and become curved and elongated to form long lens fibres. The earliest formed lens fibres are located centrally, with new fibres added in layers at the periphery. As lens fibres mature they lose their nuclei and become transparent thereby contributing to focussing light onto the retina. Lens fibres are deformable, allowing the lens to change shape (a process known as accommodation) and allow focus on close or distant objects. Magnification: x333 when printed at 10 centimetres across.