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Detect Color Blindness

Hard Color Blind Test

A tougher screen: 14 plates with deliberately lower colour contrast. A mild deficiency that slips past the standard test is more likely to show up here.

Plate 1 of 14

What number do you see?

No timer · answers stay on your device

Tip: view in good lighting at 100% screen brightness for the most reliable result.

Not a medical diagnosis. This is an educational screening tool, not a clinical exam. Screen brightness, colour settings and lighting all affect the result. For anything that matters, a driving or aviation medical, a job requirement, or a health concern, book a professional colour-vision test with an optometrist or ophthalmologist.

Why a harder test?

Short screening tests are tuned to catch clear, moderate-to-strong deficiencies quickly. Very mild anomalous trichromacy, where cones are only slightly shifted, can pass a short test. This mode adds plates with lower colour contrast and closer luminance between figure and background, which stresses colour discrimination more.

It's still a screen, not a diagnosis. A "pass" here is reassuring; a pattern of misses is a good reason to book a professional colour-vision exam. Prefer a quicker check? Use the standard test, or target a single axis with the red-green or blue-yellow test.

Frequently asked questions

What makes the hard color blind test harder?
It adds extra plates with lower colour contrast and closer luminance, so mild deficiencies that slip past a short screen are more likely to show up. It's still a screen, not a diagnosis.

Keep exploring

What next?

Take the color blind test 14 quick plates · instant type & severity · no sign-up. Start the test → See how you see colour Simulate protan, deutan, tritan & more on any image. Open the simulator → Do colour blind glasses work? Honest comparison of EnChroma, Pilestone & ColorLite. Read the guide →