... The cones are responsible for encoding color. Each cone contains structures or visual pigments sensitive to one of three avelengths of light red, green, and blue. Normal persons are able to match all colors of the spectrum by mixtures of only three fundamental color sensitivities. Hence, the huge variety of colors e perceive stems from the cone cells response to different compositions of avelengths of light. Defects in color vision occur hen one of the three cone cell color coding structures fails to function properly. One of the visual pigments may be present and functioning abnormally, or it may be absent altogether. For practical purposes, all color-deficient individuals have varieties of red or green deficiency. Blue deficiencies are very rare. Color deficient patients are not completely red or green blind. Compared to persons ith normal color vision, they have some trouble differentiating beteen certain colors, but the severity of the color deficiency is variable. Color blindness is normally diagnosed through clinical testing. See the HYPERLINK http.toledo-bend.comcolorblindIshihara.html Ishihara color test - the one most common test used Although there is no treatment for color blindness, most color deficient persons compensate ell for their defect and may even discover instances in hich they can discern details and images that ould escape normal-sighted persons. At one time the U.S. Army found that color blind persons can spot camouflage colors here those ith normal color vision are fooled by it. Ho color blindness orksThe human eye sees by light stimulating the retina a neuro-membrane lining the inside back of the eye. The retina is made up of hat are called Rods and Cones. The rods, located in the peripheral retina, give us our night vision, but can not distinguish color. Cones, located in the center of the retina called the macula, are not much good at night but do let us perceive color during daylight conditions. Many people think anyone labeled as colorblind only sees black and hite - like atching a black and hite movie or television. This is a big misconception and not true. It is extremely rare to be totally color blind. There are many different types and degrees of colorblindness, really they are color deficiencies since virtually no one is truly blind to all colors. People ith normal cones and color vision are able to see all the different colors and subtle mixtures of them by using cones sensitive to one of three avelength of light - red, green, and blue. A mild color deficiency is present hen one or more of the three cones functions poorly. A more severe color deficiency is present hen one of the cones does not function at all or is missing. Protanomaly one out of 100 males Protanomaly is referred to as red-eakness, an apt description of this form of color deficiency. Any redness seen in a color by a normal observer is seen more eakly by the protanomalous vieer, both in terms of its coloring poer saturation, or depth of color and its brightness. Red, orange, yello, yello-green, and green, appear somehat shifted in hue hue is just another ord for color toards green, and all appear paler than they do to the normal observer. The redness component that a normal observer sees in a violet or lavender color is so eakened for the protanomalous observer that he may fail to detect it, and therefore sees only the blue component. Hence, to him the color that normals call violet may look only like another shade of blue. Under poor vieing conditions, such as hen driving in dazzling sunlight or in rainy or foggy eather, it is easily possible for protanomalous individuals to mistake a blinking red traffic light from a blinking yello or amber one, or to fail to distinguish a green traffic light from the various hite lights in store fronts, signs, and street lights that line our streets. Do not let them adjust the color on the te ... Download