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Anatomy of the Eye (cont.)

IN THIS ARTICLE

Anterior Chamber

The anterior chamber is the fluid-filled space immediately behind the cornea and in front of the iris. The fluid that fills this chamber is called the aqueous humor. The aqueous humor helps to nourish the cornea and the lens.

Iris and Pupil

The iris, which is the colored part of the eye, controls the amount of light that enters the eye. The iris is a ring shaped tissue with a central opening, which is called the pupil.

The iris has a ring of muscle fibers around the pupil, which, when they contract, causes the pupil to constrict (become smaller). This occurs in bright light. A second set of muscle fibers radiate outward from the pupil. When these muscles contract, the pupil dilates (becomes larger). This occurs under reduced illumination or in darkness.

Anterior Chamber Angle and Trabecular Meshwork

The anterior chamber angle and the trabecular meshwork are located where the cornea meets the iris. The trabecular meshwork is important because it is the area where the aqueous humor drains out of the eye. If the aqueous humor cannot properly drain out of the eye, the pressure can build up inside the eye, causing optic nerve damage and eventually vision loss, a condition known as glaucoma.

Posterior Chamber

The posterior chamber is the fluid-filled space immediately behind the iris but in front of the lens. The fluid that fills this chamber is the aqueous humor. The aqueous humor helps to nourish the cornea and the lens.

Lens

The lens is a clear, flexible structure that is located just behind the iris and the pupil. A ring of muscular tissue, called the ciliary body, surrounds the lens and is connected to the lens by fine fibers, called zonules. Together, the lens and the ciliary body help control fine focusing of light as it passes through the eye. The lens, together with the cornea, functions to focus light onto the retina.

Medically Reviewed by a Doctor on 4/7/2016

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