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The Sense1 - o The fovea centralis has the highest...

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The Senses Vision Accessory Structures o The eyebrows prevent perspiration from entering the eyes. o The eyelids protect the eyes from foreign objects. o The conjunctiva covers the inner eyelids and the anterior surface of the eye. o Lacrimal glands produce tears that flow across the surface of the eye. Tears lubricate and protect the eye. Excess tears pass into the nasal cavity. o The extrinsic eye muscles move the eyeball. Anatomy of the Eye o The fibrous tunic is the outer layer of the eye. It consists of the sclera and cornea. o The vascular tunic is the middle layer of the eye. It consists of the choroid, ciliary body, and iris. o The lens is held in place by the suspensory ligaments, which are attached to the smooth muscles of the ciliary body. o The retina (nervous tunic) is the inner layer of the eye and contains neurons sensitive to light. o Rods are responsible for vision in low illumination (night vision). o Cones are responsible for color vision.
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Unformatted text preview: o The fovea centralis has the highest concentration of cones and is the area in which images are detected most clearly. o The optic disc, or blind spot, is where the optic nerve exits the eye and blood vessels enter. o The anterior compartment of the eye is filled with aqueous humor, whereas the posterior compartment is filled with vitreous humor. The humors keep the eye inflated, refract light, and provide nutrients to the inner surface of the eye. Functions of the Complete Eye o Light passing through a concave surface diverges. Light passing through a convex surface converges. o Converging light rays cross at the focal point and are said to be focused. o The cornea, aqueous humor, lens, and vitreous humor all refract light. The cornea is responsible for most of the convergence, whereas the lens can adjust the focus by changing shape (accommodation)....
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