Abstract
Receptors for vision are found in the retinal layer of the eye. Light entering the eye passes through the transparent cornea and the pupillary opening in the iris diaphragm, then through the lens to be focussed on the retina. Clear focus of light rays is achieved by refraction occurring in the cornea and the lens. The amount of light admitted to the retina is regulated by the size of the pupillary aperture, which is governed by the autonomic nervous system. Pupillary constrictor muscles in the iris are controlled by parasympathetic fibers of the oculomotor nerve, whereas pupillary dilator muscles are activated by the sympathetic nervous system.
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© 1992 Springer-Verlag New York Inc.
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Roberts, P.A. (1992). The Visual System. In: Neuroanatomy. Oklahoma Notes. Springer, New York, NY. https://doi.org/10.1007/978-1-4612-2902-5_9
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DOI: https://doi.org/10.1007/978-1-4612-2902-5_9
Publisher Name: Springer, New York, NY
Print ISBN: 978-0-387-97777-5
Online ISBN: 978-1-4612-2902-5
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