Types of Color Blindness

Prevalence: ~0.56% of the population

Protanopia is a type of red-green color blindness in which the long-wavelength (L) cones in the retina are completely absent or nonfunctional. People with protanopia cannot perceive red light, causing reds to appear dark or nearly black and making it difficult to distinguish between reds, greens, and browns.

Prevalence: ~0.67% of the population

Deuteranopia is the most common type of dichromatic color vision deficiency. It occurs when the medium-wavelength (M) cones, responsible for perceiving green light, are completely absent or nonfunctional. People with deuteranopia have difficulty distinguishing between reds and greens, though unlike protanopia, they do not experience the characteristic darkening of the red spectrum.

Prevalence: ~0.57% of the population

Protanomaly is a mild form of red-green color blindness in which the long-wavelength (L) cones are present but have a shifted spectral sensitivity, peaking closer to the medium-wavelength range. This anomalous trichromacy results in reduced ability to distinguish between reds and greens, though the effect is generally less severe than in protanopia. People with protanomaly can still perceive red but see it as less vivid and somewhat shifted toward green.

Prevalence: ~2.7% of the population

Deuteranomaly is the most common form of color vision deficiency, affecting approximately 5% of men worldwide. It is a type of anomalous trichromacy in which the medium-wavelength (M) cones are present but have a shifted spectral sensitivity, peaking closer to the long-wavelength range. This reduces the ability to distinguish between greens, reds, and yellows, though most people with deuteranomaly retain functional color vision and may not even realize they perceive colors differently.

Prevalence: ~0.003% of the population

Tritanopia is a rare form of color blindness in which the short-wavelength (S) cones, responsible for perceiving blue light, are completely absent or nonfunctional. Unlike red-green color blindness, tritanopia affects blue-yellow discrimination and is inherited on an autosomal chromosome, meaning it occurs at equal rates in men and women.

Prevalence: ~0.001% of the population

Tritanomaly is an extremely rare form of color vision deficiency in which the short-wavelength (S) cones are present but have altered spectral sensitivity. This anomalous trichromacy reduces the ability to distinguish between blue and green, and between yellow and red, though to a lesser degree than tritanopia. Because it is linked to an autosomal gene, tritanomaly affects men and women at equal rates.

Prevalence: ~0.003% of the population (approximately 1 in 30,000)

Achromatopsia, also known as rod monochromacy or total color blindness, is a rare congenital condition in which none of the cone photoreceptors in the retina function. Vision relies entirely on rod cells, resulting in a complete absence of color perception, extreme sensitivity to light (photophobia), and significantly reduced visual acuity. It is the only form of color blindness in which the individual truly sees in grayscale.