Eye
Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptor cells in conscious vision connect light to movement. In higher organisms the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in molluscs, chordates and arthropods.
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Famous quotes containing the word eye:
“And all my days are trances,
And all my nightly dreams
Are where thy dark eye glances,
And where thy footstep gleams—
In what ethereal dances,
By what eternal streams.”
—Edgar Allan Poe (1809–1849)
“But the lightning which explodes and fashions planets, maker of planets and suns, is in him. On one side elemental order, sandstone and granite, rock-ledges, peat-bog, forest, sea and shore; and on the other part, thought, the spirit which composes and decomposes nature,—here they are, side by side, god and devil, mind and matter, king and conspirator, belt and spasm, riding peacefully together in the eye and brain of every man.”
—Ralph Waldo Emerson (1803–1882)
“The master’s eye is the best fertilizer.”
—Gaius Plinius Secondus (c. 23–79)