The most common cause of color blindness is genetic. More men are affected than women, as the gene that is affected is on the X chromosome. Women have two X chromosomes, so even if they have the defect on one chromosome, their other X chromosome compensates. Men only have one X chromosome as they are XY.
Red-green is the most common form of color blindness, and affects up to 8% of men and 0.5 % of women. Yellow-blue color blindness is more rare.
Color blindness can affect the ability of a person to become a pilot, train driver, or member of the military. Color blindness can affect the ability to tell the red and green on traffic lights.
There are now special lenses and phone apps that have been developed to help patients who are color blind.
Famous people who were color blind include Bill Clinton, Paul Newman, and Mark Zuckerberg.
Diagnosis can be made with the Ishihara color blindness test. Can you see the 74?