The Real Reason Not Everyone Can See Color
It's strange to think that one person might not see color the same way that someone else does. After all, isn't color an objective property of the world? Research is showing that that isn't necessarily the case. In fact, how someone experiences colors can be affected by many factors, including gender, location, ethnicity, and, most importantly, genetics, according to Psychology Today.
Humans see color through photoreceptors in the retina called cones which are receptive to red, green, or blue light. Within the cones are pigments that let us see color, explains the American Optometric Association (AOA). People with a color deficiency don't have enough pigments that allow them to see certain colors. These deficiencies include red-green, the most common version, blue-yellow, or complete color blindness which is only being able to see black and white or shades of grey. Color deficiency can occur for many reasons, but one reason stands out.
Genetics play a huge role in how people see color
In the majority of cases of color deficiency, genetics is the cause. Around 8% of white men are born with some amount of color blindness while only 0.5% of women are, according to the American Optometric Association. The reason for this is that the red-green color blindness gene, the most common, is only passed down through the X chromosome.
As the National Eye Institute explains, males receive one X chromosome from their mother. If the chromosome they inherit contains the red-green color blindness gene, then that's what the male will be born with. Because females have two X chromosomes, one from their mother and father, both would need to have the color-blindness gene for the female to be affected. The other types of color deficiency, such as blue-yellow and complete color blindness, come from different chromosomes, so males and females have equal chances of being affected.
Other causes for color deficiency include aging, certain medications, and some diseases, such as sickle cell anemia and Alzheimer's, according to Mayo Clinic.