ABSTRACT
The eye is a unique organ, from an anatomical and physiological point of view, in that it contains several highly different structures with specific physiological functions. This chapter provides a condensed general view of the anatomy and physiology of the eye much from the perspective of ocular drug delivery. The anterior segment of the eye comprises the cornea, conjunctiva, iris, ciliary body, the anterior and posterior chambers, and the lens. The cornea is the anteriormost transparent membrane of the eye continuing posteriorly as the sclera. The corneal epithelium contains large amounts of acetylcholine and choline esterases. The corneal endothelium is a single dell layer facing the anterior chamber. The conjunctiva can be regarded as a mucous membrane covering the inner surface of the eyelids and the visible part of the sclera. The eyelids consist of four main layers: the skin, the muscle layer, a layer of fibrous tissue or the tarsus, and the conjunctiva.
