What is the most common form of colorblindness?

The most common form of colorblindness is red-green colorblindness. This condition is primarily due to the presence of deficiencies in the red and green photoreceptors in the retina, which impairs the ability to differentiate between these two colors.

Red-green colorblindness is classified into two main types: protanopia, which is a lack of red cones, and deuteranopia, which is a lack of green cones. These types of colorblindness affect a significant portion of the population, particularly men, as the genes responsible for these receptors are located on the X chromosome. Since males have only one X chromosome, they are more likely to express colorblindness than females, who have two X chromosomes and may have a backup if one X carries the gene for color blindness.

This makes red-green colorblindness the most prevalent form, affecting roughly 8% of men and about 0.5% of women of Northern European descent. Other types of colorblindness, such as blue-yellow or total color blindness, are less common in the general population.