Colorblindness occurs when one or more types of cone cells in the retina are either missing or don’t function properly. The most common forms are:
- Red-green colorblindness (deuteranomaly or protanomaly) – difficulty distinguishing between reds and greens
- Blue-yellow colorblindness (tritanomaly) – rare condition affecting blue and yellow perception
- Complete colorblindness (achromatopsia) – seeing only in grayscale
This condition is usually genetic and affects approximately 8% of males and 0.5% of females worldwide. The higher prevalence in males is because the genes for red and green color vision are located on the X chromosome, and males only have one X chromosome to rely on.