Anterior Chamber-The space in the eye bounded in front by the cornea and in back by the iris and middle part of the lens; contains the aqueous humor
Aqueous Humor-The transparent fluid occupying the anterior compartment (the space between the cornea and the crystalline lens) of the eye; produced by ciliary epithelium and circulates into the posterior chamber (between the iris and the crystalline lens), through the pupil, into the anterior chamber (between the cornea and the iris), and out of the eye through the trabecular meshwork and canal of Schlemm; nourishes the lens and epithelial cells
Choroid-A vascular membrane containing large branched pigment cells that lies between the retina and the sclera of the eye
Ciliary Body-An annular (ring-like) structure on the inner surface of the anterior wall of the eyeball, contained within the uveal tract and composed largely of the ciliary muscle and bearing the ciliary processes
Ciliary Muscle-A circular band of smooth muscle fibers situated in the ciliary body and serving as the chief agent in accommodation when it contracts by drawing the ciliary processes centripetally and relaxing the suspensory ligament of the crystalline lens, permitting the lens to become more convex
Conjunctiva-The mucous membrane that lines the inner surface of the eyelids and the sclera on the front of the eyeball
Cornea-the transparent, anterior, dome-shaped portion of the eyeball that covers the iris and pupil, acting like a window which admits light into the eye
Iris-the opaque muscular contractile diaphragm that is suspended in the aqueous humor in front of the lens of the eye; perforated by the pupil and continuous peripherally with the ciliary body; possesses a deeply pigmented posterior surface, which excludes the passage of light except through the pupil, and a colored anterior surface which determines the color of the eye
Lens-Highly transparent biconvex, nearly spherical body that focuses light rays entering the eye typically onto the retina
Macula-A small and highly sensitive part of the retina responsible for detailed central vision.
Optic Nerve-Cranial nerve; the sensory nerve which carries electrical impulses from visual stimuli in the retina out of the eye, across the optic chiasm, and to the ventral part of the diencephalon, on their way to the visual cortex in the occipital cortex of the brain for interpretation
Pupil-The contractile, usually round aperture in the iris of the eye which allows light to pass into the crystalline lens
Posterior Chamber-A narrow space inside the eye, located behind the peripheral part of the iris and in front of the suspensory ligament of the lens and the ciliary processes; contains aqueous humor
Retina-Layer of nervous tissue, covering the back two-thirds of the eyeball, in which stimulation by light initiates an electrochemical reaction in which electrical impulses are transmitted to the brain, producing the sensation of vision; actually an extension of the brain, formed embryonically from brain tissue and connected to the brain proper by the optic nerve
Vitreous Humor-The transparent gelatinous mass occupying the posterior compartment (the space between the crystalline lens and the retina of the eye) which is enclosed by a delicate hyaloid membrane; composed of water (99%), collagen fibrils, highly hydrated hyaluronic acid, halocytes, inorganic salts, sugar, and ascorbic acid; produced by halocytes located peripherally in the vitreous body
Glossary of Terms
Blood Eye Barrier (BEB)-Controls the passage of substances from the blood into the eye. It is a physical barrier between the local blood vessels and most parts of the eye itself, and stops many substances from traveling across it. The blood-ocular barrier normally keeps most drugs out of the eye. Inflammation can break down this barrier allowing drugs and large molecules to penetrate into the eye.
Cataracts-A clouding of the lens in the eye that affects
vision. Most cataracts are related to aging, and are common
in older people. By age 80, more than half of all Americans either have
a cataract or have had cataract surgery.
Cytokines-Signal molecules that are used extensively in immune
system cell communication. Include interleukin, tumor necrosis factor,
and interferon.
Interleukin-1 (IL-1)-Cytokine that is part of the body’s inflammatory response.
Interleukin-1ra-IL-1 inhibitor that binds to the same receptor
on the cell surface as IL-1, and thus prevents IL-1 from sending a
signal to that cell (used in TheraKine's EpiKine™).
Glaucoma-An eye disease in which the normal fluid pressure inside the eyes slowly rises, leading to vision loss--or even blindness.
Neovascularization-The growth of new, abnormal blood vessels. These blood vessels are often fragile, and can leak fluid.
Tumor Necrosis Factor (TNF)-A cytokine that is produced in response to toxins, mediates inflammation, induces the destruction of some tumor cells and the activation of white blood cells.
For more information of the eye and its parts see:
NEI's Glossary of Vision Related Terms
NEI's Diagram of the eye
Eye definitions courtesy of tedmontgomery.com
Fig. 1.1 courtesy of medicinenet.com