How do I know if I am colour blind?

Take an Ishihara-style plate test and see whether you can read the hidden numbers. Difficulty with red-green plates is the most common sign, but only an eye doctor can diagnose it.

What are the types of colour blindness?

The most common is red-green (protan and deutan types). Blue-yellow (tritan) is rarer, and total colour blindness is very rare.

Are online colour blindness tests accurate?

They give a useful indication but not a clinical diagnosis. Screen calibration and lighting affect colours, so confirm any result with an optometrist.

How to Test for Color Blindness Online (Free)

Quick answer: To test for colour blindness online, view a series of Ishihara-style colour plates and report the number or shape you see in each. It gives a quick, free indication of red-green or blue-yellow deficiency — but only an eye doctor can give a clinical diagnosis.

Try it now: open the colour blindness test and read each plate in good, neutral lighting.

How the online test works

The test shows Ishihara-style plates — circles of coloured dots with a number or shape hidden inside using a contrasting colour. People with normal colour vision read the figure easily; those with a colour deficiency see a different number or none at all.

Types of colour blindness

Red-green deficiency is by far the most common and comes in two main forms, protan (red) and deutan (green). Blue-yellow deficiency (tritan) is much rarer, and complete colour blindness, where no colours are distinguished, is very rare.

How accurate is an online test?

Treat the result as an indication, not a diagnosis. Monitor calibration, brightness and room lighting all shift how colours appear on screen, so a clear result still warrants a proper exam. An optometrist uses calibrated plates and other tests to confirm the type and severity.

Can colour blindness be corrected?

There is no cure, but it is usually mild and manageable. Some people find specialised lenses help them distinguish certain colours, and apps and accessibility settings can label or adjust colours on devices.

Take the test

Run the colour blindness test to see how you do, and book an eye exam if the result or everyday colour confusion concerns you.