Can Women Be Color Blind?
Can women be color blind? Yes, but the chances are slim! Women can be color blind but occurs in only about 1 in 200 women (compared to 1 in 12 men)*. As a result, approximately 95% of people with color blindness are men. Thanks to chromosomal differences between men and women, color blind women are much fewer and farther between than color blind men.
What Gene Causes Color Blindness?
Red-green color blindness is a sex-linked genetic mutation on the OPN1LW or OPN1MW gene that is passed on the X chromosome. Females have two X chromosomes so if a woman inherits one normal X chromosome and one with the mutation, she won’t display the mutation since it is a recessive gene. Males are more likely to be color blind since they don’t have a second X chromosome to override the chromosome that carries the mutation.
Is Color Blindness Inherited from the Mother or Father?
Women can be carriers of the color blind gene and pass the mutation down the family line. If only the father is color blind, there is a 100% chance that his daughters will carry the gene, but they will not be color blind themselves. His sons will neither carry the gene nor be color blind.
Is the color blind gene recessive?
Yes, the color blind gene is recessive, meaning that if you are a woman and only one of your X chromosomes has a color blind gene condition, you will be a gene carrier, but will not be color blind. If the mother carries the gene but is not color blind, there is a 50% chance that her sons will be color blind and a 50% chance that her daughters will carry the gene.
When a color blind father and a mother who carries the color blind gene have children, there is a 50% chance that their sons will be color blind. Their daughters, however, will have a 50% chance of being color blind and 100% chance of being carriers of the gene.
Alternatively, a color blind mother and a non-color blind father will have all color blind sons and will have daughters who all carry the color blind gene.
Finally, if both parents are color blind, their sons and daughters have a 100% chance of being color blind and their daughters have a 100% chance of carrying the gene.
Of the approximately 300 million color blind people in the world, it is estimated that 95% are men. Now that you have learned how is color blindness inherited and how genes are passed, it's easy to see why women can still have color blindness.
Learn more about color blindness and EnChroma glasses
* For people of Northern European ancestry.