The eye is a complex sensory organ specialized in collecting visual information. The eye is made up of three main parts: the eyeball (globe), the orbit (orbit), and accessory (adnexal) structures. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the Original Essay Accessory Structure The accessory structures of the eye include the eyelids, conjunctiva, caruncle, and lacrimal glands. The eyelids are folds of skin that cover and protect the eye. It contains glands that produce an oily secretion which, in turn, covers the tear layer and prevents tears from evaporating and the eyelids from sticking together. The conjunctiva is a transparent mucous membrane that lines the inner surface of the eyelids and the outer surface of the eye. The conjunctiva secretes mucus to lubricate the eyeball and keep it moist. The caruncle is the small pinkish part of the innermost corner of the eye that contains the oil and sweat glands as well as the conjunctival tissue. The lacrimal gland (lacrimal gland) is located in the upper outer corner of each eye. The lacrimal gland secretes tears to keep the surface of the eye and the lining of the eyelids moist and lubricated. Tears help reduce friction, remove dust and debris from the eye, and prevent infections. Orbit (eye socket) The orbit (eye socket) is made up of bone formed from the skull that contains the eyeball and connective tissues. Bones and connective tissues cushion and protect the eye. Muscles attached to the eyeball make it move in different directions. The eyeball The eyeball (globe) is rich in blood vessels. Human eyes are roughly spherical and filled with a transparent gel-like substance called vitreous humor. It supports internal structures and maintains the shape of the eye. Keep in mind: this is just a sample. Get a personalized paper now from our expert writers. Get a Personalized Essay The eyeball is made up of three concentric layers (tunics), whose names reflect their basic functions: a fibrous tunic, made up of the sclera behind and the cornea in front; a pigmented vascular tunic, including the choroid, ciliary body and iris; and a nervous tunic, the retina.