{"id":2531,"date":"2016-02-20T06:31:46","date_gmt":"2016-02-20T13:31:46","guid":{"rendered":"http:\/\/susanbgraham.com\/blog\/?p=2531"},"modified":"2016-04-17T16:07:52","modified_gmt":"2016-04-17T23:07:52","slug":"seeing-color-colorblind","status":"publish","type":"post","link":"http:\/\/susanbgraham.com\/blog\/2016\/02\/20\/seeing-color-colorblind\/","title":{"rendered":"Seeing Color Colorblind"},"content":{"rendered":"
This entry is part [part not set]<\/font> of 4 in the series Seeing Color Colorblind<\/a><\/div>

Seeing Color Colorblind<\/h4>\n<\/p>\n

Seeing color is something that those of us with normal color vision take for granted. But many people do not see the range of colors seen by most people. “Colorblind” has been applied to such people, people with a color deficiency. As my son has said, <\/p>\n

“‘colorblind’ as a term is sort of a misnomer in that even extremely colorblind people see colors – they just see them differently than people who are not colorblind. Unfortunately, many people are ignorant regarding this.”<\/p><\/blockquote>\n

Different kinds and degrees of color deficiencies have been lumped under “colorblindness.” Most color deficiencies are inherited genetically, as an X-linked recessive trait. The genes that produce the photopigments in the cones of the retina, required for color vision, are located on the X chromosome. A female has two X chromosomes. If one is defective but the other normal, in most cases she will have normal color vision. Males, on the other hand, have one X chromosome. The Y chromosome has no matching parts that produce photopigments, so a male who inherits a X chromosome with the defect will be colorblind. Males inherit the X chromosome from their mother, the Y from their father. Females inherit one X chromosome from their mother, and one X chromosome from their father. If a woman’s father is colorblind, she will inherit a color deficient X chromosome from him. If we assume for the moment that the X chromosome she inherits from her mother is normal, the probably that the abnormal X will be passed on to her children is 50%, and the probability that the normal one will be passed on is 50%. Any of her sons have a 50% chance of inheriting their maternal grandfather’s color deficiency through their normal color sighted mother.<\/p>\n

That was the situation in my family. My father was colorblind, and I knew early on that any sons of mine had a 50% probability of being colorblind. So, it was no surprise when he was colorblind. I’ve always been glad that they had a close relationship, because they saw the world in the same way and could talk about it. My father laughed about being colorblind. He was a child of the Great Depression, and his father had died when he was three, so I guess there were a lot worse things in his childhood than being colorblind.<\/p>\n

Although I knew they both had the same “red-green” colorblindness, until quite recently I really had no idea exactly how they saw the world. It just was, and nothing could be done about it. All of that changed in March of 2015, when Enchroma<\/a> posted a video on YouTube:<\/p>\n

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