Light micrograph of a longitudinal section through an eyelid. The upper outermost layer is the epidermis (red) of the skin, while the lower outermost layer, which is in contact with the eye, is a mucous membrane. Mucous cells (light blue spots) in the mucous membrane help to keep the eye moist. At centre right is the hair follicle of an eyelash (red). Muscles, which are responsible for the movement of the eyelid, are orange. Across bottom are meibomian glands (pink), and ducts (white). The secretions of these glands lubricate the eyelid. Collagen fibres are blue. Magnification: x30 when printed at 15cm wide.