| Show I i E YL > 2 xLjt J The eye Is really avery much improved I proved snapshot camera and our little i friends who have been vainly longing for cameras in order to take photographs photo-graphs of many things that Interest and amuse them can be partially 1 comforted com-forted by the thought that they have J a twin camera In their own head that I i is better in every way than the weak imitations that are for sale The eye Is a combination of narts so beautifully I beauti-fully arranged that no imitation by I men can ever hope to equal the photographic photo-graphic power of sight Its parts can be more easily understood by comparing compar-ing them with the 1 different parts of a camera which Is 1 really a mechanical eye but very Inlp9rfcct when compared I to your own The entire eye f R generally known as the eyeball This is almost roundabout round-about an Inch diameter but with a I slight bump in front much as H I a little slice of smaller ball had been pasted on to the side of a ball ten times as1 I large This bump Is transparent and serves the same purpose as the outer lens of a camera The rest of the eyeball eye-ball Is not transparent and serves asa as-a framework and to keep out light from the sensitive parts within Just as does the out derbox part of a I camera It is made of three coats 1 The outer coal is tough firm and white and is generally called the white of the eye It keeps the eye In its proper roiind shape and to It are fastened the muscles which move the eye from side to side The middle coat Is dark something like a grape skin and is lined with flat darkbrown cells These cells absorb very strong I rays of light which enter the eye and would Interfere with a clear view by dazzling tho sight and serves the same purpose as the black inside lining of a camera In tho front of the eye this coat forms the Iris the colored part of the eye sometimes blue gray hazel brown or J black and performs I the same duties as the shutters of a camera j j In the center of this is a transparent 1 dot called the pupil which looks black I but is really without any color but in j looking at any ones eye we look J through the pupil into the dark cham her behind It just as we look through j I the Inner lens of a camera which also I r appears to be black It serves the purpose I pur-pose of a second lens and it brings I closer to a point the rays of light that I enter through the outside lens of the I little bump I The < lcoal inside of the other two Is the retina which Is really a II spreadout end of > a nerve called the I optic nerve leading directly to tho t brain Inside of thfs and just behind the irlp Is a jellylike substance that Is shaped exactly like a magnifying glass Its use Is to bring the rays of light that enter the eye to a sharp point or focus on the back part of the rotina This Is called the crystalline lers and Is onequarter of an inch thick Just behind this lens is a mass of perfectly transparent jellylike matter which completely fills the third coat or retina This is to act as a support for the outside coats and to support the chryslallino lens in front and the very delicate part of the retina behind This I part of the retina Is just like the semi I I live plate of the camera Rays of light coming Into the eye through the differ I I en lenses are brought to a point on the I retina forming a picture just as they do in a camera If you look through I the back of a camera you will see on the groundglass plate the picture made by the rays of light that come through I the lens In front This is Just such a I I picture as is made on the sensitive plate of the eye the retina I I As the retina Is really the end of the j nerve these pictures are flashed j straight to the brain where they are labeled and we are told what they are I i I If the optic nerve should be cut there would be no Impression taken to the I brain and we could not see even al j i though the pictures would be on the retina just the same that would be just as if a camera tried to take a picture pic-ture nil by Itself with no one to help It There would be a picture on the sensitive sensi-tive plate but no one to tell what kind of a picture it was If the optic nerve were bruised or Injured there would boa bo-a picture on the retina as usual but the nerve would carry a wrong impression impres-sion to the brain the brain would of course label It wrong and you would think you saw something very different from what you really did see For instance in-stance instead of saying There is I Frank Gusterts bobtailed bull pup the brain might say Goodness gracious gra-cious There Is Mr Stickless barn sliding down hill on Mr Tucks oxcart I cart The optic nerves leading from both eyes Join and go to the brain as one I nerve In this way as both eyes hava the same picture on their retinas the brain receives the picture doubled In I strength and clearness |
