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.
Read more about Eye.
Famous quotes containing the word eye:
“What do the botanists know? Our lives should go between the lichen and the bark. The eye may see for the hand, but not for the mind. We are still being born, and have as yet but a dim vision of sea and land, sun, moon, and stars, and shall not see clearly till after nine days at least.”
—Henry David Thoreau (1817–1862)
“I have proceeded ... to prevent the lapse from ... the point of blending between wakefulness and sleep.... Not ... that I can render the point more than a point—but that I can startle myself ... into wakefulness—and thus transfer the point ... into the realm of Memory—convey its impressions,... to a situation where ... I can survey them with the eye of analysis.”
—Edgar Allan Poe (1809–1849)
“The world is filled with the proverbs and acts and winkings of a base prudence, which is a devotion to matter, as if we possessed no other faculties than the palate, the nose, the touch, the eye and ear; a prudence which adores the Rule of Three, which never subscribes, which never gives, which seldom lends, and asks but one question of any project,—Will it bake bread?”
—Ralph Waldo Emerson (1803–1882)