![]() ![]() The sclera is the white part of the eye that surrounds the cornea and is continuous with it. In other words, the conjunctiva is a thin transparent membrane that covers the sclera. The conjunctiva also covers the moist back surface of the eyelids and eyeballs.” It has three segments: the iris, the ciliary body and the choroid. ![]() “Near the front of the eye, in the area protected by the eyelids, the sclera is covered by a thin, transparent membrane (conjunctiva), which runs to the edge of the cornea. The uvea is the pigmented middle layer of the eyeball. The conjunctiva helps protect the eye by keeping small foreign objects and infection-causing microorganisms out and by contributing to the maintenance of the tear film.” The pupil is the opening through which light enters the eye.Ĭonjunctiva: “The conjunctiva is the membrane that lines the eyelid and loops back to cover the sclera (the tough white fiber layer covering the eye), right up to the edge of the cornea (the clear layer in front of the iris and pupil-see Structure and Function of the Eyes). The pupil appears as a black hole at the center of the iris. It acts as a diaphragm, like a shutter on a camera, regulating the amount of light that enters through the pupil. Iris: The iris is located behind the cornea. It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil.” Pupil: “The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina. Najeeb’s lectures on the Structure and Function of the Human Eye. ![]()
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