color blindness

Until about three months ago I thought a person who was colorblind was just that blind to color and saw the world in black and white. Contrary to my belief, a person who sees life through black and white lens (monochromasy) is extremely rare. There are many different types of colorblindness- a more technical term is called color vision deficiencies. People with normal cones, light sensitive pigments, able to see different hues and subtle mixes of them are referred to as trichomasy. A person who is week to green shades is referred to as Deuteranomaly. They have trouble distinguishing small differences in colors in the red, yellow, orange and green area of the spectrum. Many Deuteranomalous people have no problem getting through life, in fact some do not notice that their color perception is in any way different from normal. On the other hand people with Dichromasy usually know they have a color perception problem. They see no difference between red, orange, yellow, and green. So we can see how this could cause problems in daily living. Protanopia is another color vision deficiency, where the brightness of red, orange, and yellow are reduced compared to normal. The dimming can be very pronounce that people maybe confuse red with black. Lavender, violet, and purple are indistinguishable from many shades of blue because of the reddish component is so dim it appears invisible.