The eye


The bulb of the eye and its muscles and the optical nerve connecting it to the brain are all situated in the optical cavity of the crane. The exterior part of the eye consists of firm layers of connective tissue, the white sclera and the transparent cornea. The lids of the eye contain multiple glandular structures. Its base is formed by a solid elongated plate of dense connective tissue (tarsus) carrying the eyelashes. The tarsi are attached to the frontal process of the maxillary bone by the - clearly visible! - internal tarsal ligaments. The tarsi also contain the commencements of the lachrymal ducts (puncta lacrimalia) located near the medial border of the eye - the lower one being easy to recognize - leading to the nasal cavity. The lachrymal gland is located in the lateral upper part covered by the upper lid. Medial to the puncta lachrymalia sits the caruncula lacrimalis, a small glandular body. All the glandular structure of the eye contribute to its so unique glance.

The levator palpebrae opens the eye, orbicularis palpebrarum closes the eye (not shown).

Darkness and emotion induce dilation of the pupil by the smooth muscles of the iris, brightness causes constriction.

The space above the eye increase in the elderly by tissue atrophy involving also the eye itself. Below the eye tissue atrophy leads occasionally to the accumulation of water. These effects together with wrinkles and skin folds contribute considerably to the expression of sorrow and crumbling health in the facial expressions of elderly people.