Physiology
The eye's blind spot is a result of the absence of photoreceptors in the area of the retina where the optic nerve leaves the eye.
Each human optic nerve contains between 770,000 and 1.7 million nerve fibers, which are axons of the retinal ganglion cells of one retina. In the fovea, which has high acuity, these ganglion cells connect to as few as 5 photoreceptor cells; in other areas of retina, they connect to many thousand photoreceptors.
Read more about this topic: Optic Nerve
Famous quotes containing the word physiology:
“Now the twitching stops. Now you are still. We are through with physiology and theology, physics begins.”
—Alfred Döblin (1878–1957)
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—Samuel Butler (1835–1902)
“If church prelates, past or present, had even an inkling of physiology they’d realise that what they term this inner ugliness creates and nourishes the hearing ear, the seeing eye, the active mind, and energetic body of man and woman, in the same way that dirt and dung at the roots give the plant its delicate leaves and the full-blown rose.”
—Sean O’Casey (1884–1964)