eye. i

The organ of vision, situated in the orbit. It consists of the eyeball, bulb or globe of the eye, the prolongation of the optic nerves, and the six extrinsic muscles, four straight and two oblique. It is a spherical body, and consists of three tunics; ist. cornea and sclera; 2d. iris, ciliary proce es, and choroid; 3d. retina. Within these tunics are contained three refracting media, the aqueous humor, lens and capsule, and vitreous humor. The cornea and sclera are fibrous in structure and form the outer coat; the middle coat, formed of iris, ciliary proce es, and choroid, is mainly a muscular, vascular, and pigmented coat, while the retina is mainly a nervous structure, being an expansion of the optic nerve fibers [B. N. A., oculusl. amaurotic cat's e. See amaurosis, artificial e. An e. usually made of gla or porcelain, but sometimes of hard rubber or celluloid. It is inserted in the orbit from which the eyeball has been removed, or, in cases where the stump still remains, for purely cosmetic F. 1. The chemical symbol of the element fluorin. 2. An abbreviation for Fahrenheit. 3.Abbreviation for fiat, let there be made, or make.