眼睛的功能（Eye function）.docVIP

眼睛的功能（Eye function） How do the eyes see things? We know that everyone has two eyes, and everyone uses them. But how do the eyes see things? Physiology tells us that human vision is accomplished by the combined activity of the eye, optic nerve and visual center. The eye is the peripheral organ of the vision, and is a special sense of light wave as a proper stimulus. The external light from objects, through the transparent tissue eye refraction and image formation in the retina; retina by light stimulation, cause a series of physical and chemical changes in the treated cells, and produce a potential change, this change is called a potential receptor potential, through the transfer of bipolar cells and so on, can the ganglion cell generates a pulse signal, and convert light into nerve impulses through the optic nerve impulses into the visual cortex, causing vision. Therefore, the eye has two functions: refraction, imaging and transducing. Since the French invented the worlds first optical camera in 1826, some people compared the human eye to a live camera, because the camera had lens, iris, camera obscura, film and adjusting device. The same is true of the structure of the human eye, the cornea and lens equivalent to the lens, the pupil is equivalent to the aperture, the choroid equivalent of the camera, the retina equivalent to the film. This formulation has been in the past nearly a hundred years, but it still has been highly recommended by the medical profession, because such comparisons seem very reasonable. But in recent years, somehow? The eyes of modern people become more and more short-sighted. Some people think it hurts to read when reading in dim light. Norman, a German eye doctor, explained that reading while reading in dim light is a widespread wrong idea. When light is bad, the eyes and the brain are more tense than normal, but they do not do any harm to the eyes. Its like taking pictures in the dark, though the photos are not bright, but the camera is not