How to take the color blind test
- Turn off night mode, blue-light filters and color-changing accessibility settings, and set your screen to normal brightness.
- Look at each circle of dots for a few seconds and type the number you see. If you see no number, tap I don't see a number.
- After 10 plates you get a score and a screening result. Share it and see how your friends do.
How the plates work
Like the Ishihara plates used by eye doctors since 1917, each plate hides a number made of dots that differ from the background mainly in hue, while their lightness is similar. People with typical color vision see the number easily; people with red-green color vision deficiency (protan or deutan types) see dots of similar color and struggle to find it. Two control plates use high contrast that everyone should read; if you miss those, the result is marked as inconclusive. One plate tests blue-yellow (tritan) vision, which is much rarer.
The plates are generated fresh each time with random numbers, so you cannot memorise them. Because every screen shows colors differently, an online test can only screen, not diagnose. Printed Ishihara books, anomaloscopes and the Farnsworth D-15 test performed by an optometrist are the reliable methods.
About color blindness
About 1 in 12 men and 1 in 200 women have red-green color vision deficiency, mostly inherited through the X chromosome. Most people with it can see colors, just with less distinction between reds, greens, browns and oranges. To see how images look with it, try the color blindness simulator.
How accurate is an online color blind test?
It is a useful screening tool, but screen calibration affects the colors. See an optometrist for a diagnosis.
I scored low. What should I do?
Retake the test with night mode off and brightness up. If you still miss red-green plates, ask an optometrist for a proper color vision test.
Can color blindness be cured?
Inherited color blindness cannot be cured, but special tinted glasses can improve contrast between some colors for some people.