It is vitally important that the front surface of the eyeball, the cornea, remain moist. This is achieved by the eyelids, which during waking hours sweep the secretions of the lacrimal apparatus and other glands over the surface at regular intervals and which during sleep cover the eyes and prevent evaporation.
The lacrimal system comprises of a series of anatomical structures with specific physiologic properties.
Eyelid eversion is used to expose the superior palpebral conjunctiva and fornix, so that foreign matter can be identified in these areas.
The optic pathway includes the retina, optic nerve, optic chiasm, optic radiations, and occipital cortex (see figure Higher visual pathways ).
Orbital rim
– Borders of orbit
– Roof, floor, base, apex, medial and lateral walls of orbit
– Superior orbital fissure
– Inferior orbital fissure
– Superior orbital foramen
