Colour vision deficiency affects roughly 1 in 12 men and 1 in 200 women of Northern European descent, primarily as reduced red-green discrimination — though prevalence varies by population. The simulations below show one representative point on a spectrum that varies continuously between individuals; they are not a diagnosis or a measurement of any specific person’s vision.
This is a simulation, not a measurement of any specific person’s vision — severity varies continuously and individually, especially for the “-anomaly” types.
Original (typical vision)
Protanopia
Complete absence of red-sensing (L-cone) photoreceptors — reds, oranges and greens are hardest to distinguish.
Protanomaly
Reduced sensitivity in red-sensing photoreceptors — a milder, partial version of protanopia.
Deuteranopia
Complete absence of green-sensing (M-cone) photoreceptors — the most common form of red-green colour blindness.
Deuteranomaly
Reduced sensitivity in green-sensing photoreceptors — the single most common colour vision deficiency overall.
Tritanopia
Complete absence of blue-sensing (S-cone) photoreceptors — rare; blues and yellows are hardest to distinguish.
Tritanomaly
Reduced sensitivity in blue-sensing photoreceptors — a milder, rare form of tritanopia.
Achromatopsia
Complete absence of colour vision — extremely rare; the world is perceived only in shades of grey.