How+do+people+become+colour+blind??


 * __HOW DO PEOPLE BECOME COLOUR BLIND?__**

Answer the question below, append new answers to the top of this page. _ __Response 1:__ Colour blindness usually comes from your family. The average human retina has two types of light cells; rod cells (which is active in low light), and cone cells (which is active in normal daylight). However genes that have to do with colour vision are on the X chromosomes. This is why colour blindness is more common in males than females. Females have 2 Y chromosomes, that way, if they would have to have 2 defective Y chromosomes in order to go colour blind, in other words, both the father and mother must be colour blind, or the mother is a carrier of this gene. A male has both a Y chromosome and an X chromosome. They always inherit their colour blindness from their mother, who usually is not colour blind, therefore is a carrier. There are 3 main types of colour blindness; Monochromacy, where a person is truly colourblind and connot distinguish colours such as blue, red, green, or yellow, and they can only distinguish colours based on brightness. This person would see the world in black, white, and grey. To inherit this, you would have to have both parents with colour deficiency. Dichromacy, is a less severe type of colour blindness where they can tell colours such as reds and blues apart. Protanopia, is where greens, yellows and reds are confused due to insensitivity to red light. So far, researchers have not found a cure for inherited colour vision defects because they are due to missing or incorrect visual pigments. However, special aids have been developed to help colour vision defects tell between certain colours, for example, a specially tinted eyeglass. This, however, does not cure them.
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 * How do people become color blind? **
 * Karen T.**

Reference

“Colour Blindness” on November 22, 11 from the Internet on the site: []

“Why are you colour blind?” By Dr. Terrace Waggoner, a colour vision expert. Found on November 22, 11 from the Internet on the site: []

For usage of any //Eye Facts// content or illustrations please contact the Office of Medical Illustration at eyeweb@uic.edu or 312-996-5309 for licensing found on November 22, 11 from the Internet on the site: []

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