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Showing posts from September 18, 2011

The Eye -- Its Anatomy and Physiology III -- Lesson 263

In the recent post you have learned about the rods and cones.An optic nerve is the nerve of which light energy is focued on the retina, a chemical change occurred in the rods and cones initiating nerve impulseswhich travel from the eye to the brain via the optic nerve. The region in the eye where the optic nerve meets the retina is called retina is called the optic disk. This optic disk is otherwise called as the blind spot of the eye. A small oval which is called the macula is yellowish area to the side of the optic disk.  A central depression which is called fovea centralis is also contained in it. which composed of largely of cones, and is the location of sharpest vision in the eye.  If fovea's portion or macula's portion is damaged, central vision blindness occurs and the vision is reduced. Through the opthalmoscope the fundus of th eye is the posterior and the inner part is visualized.  The rods and cones in the retina synapse with neurons and leads to the optic