Am I color blind?
About 1 in 12 men and 1 in 200 women have some form of color vision deficiency, and many don't know it. Color blindness rarely means seeing in black and white. Usually certain colors look more alike than they should: reds and greens, or blues and yellows. People often find out when they mix up colored wires, rate a steak's doneness or read a chart with red and green lines.
Types of color blindness
Protan (red-weak or red-blind): reds look darker and duller, and are easily confused with greens and browns. Deutan (green-weak or green-blind): the most common type, where greens, yellows, oranges and reds can look alike. Tritan (blue–yellow): rare, with blues confused with greens and yellows confused with pinks.
Each type can be mild (anomalous trichromacy, where one type of cone is shifted) or strong (dichromacy, where one type of cone is missing). This test reports both the type and the strength.
How this color blindness test works
The plates are generated from a model of how the eye's cones respond to light (Viénot, Brettel & Mollon, 1999). For each type, the hidden number and the background are chosen so that they look identical to someone with that deficiency. Three plates per type, at decreasing strength, show how strong it is. A control plate that everyone should see checks that your screen is working.
For the best result use both eyes, wear your glasses, turn brightness up and switch off Night Shift, True Tone and any color filters.
What to do with your result
Inherited color blindness is lifelong, doesn't get worse and isn't a health problem in itself. It's still worth knowing, for driving, careers that require normal color vision, and telling teachers if your child is affected. If your color vision has changed recently, or differs between your two eyes, see an eye doctor, because acquired color changes can be a sign of eye or nerve disease.