AtlasVision

Colour vision on a screen, not a diagnosis

Colour vision on a screen: a plate check and a guide

A colour vision check with 24 original dot plates, and a guide to the Ishihara test: what plates show, what a screen cannot, and when to see an eye doctor.

Colour vision check

Twenty-four dot plates, red-green and blue-yellow, with control plates for your screen.

About three minutes, no ads, and nothing saved. The result names a pattern and says what a screen cannot tell you.

Start the colour vision check

What these tests can and cannot tell you

The colour vision check on this site shows twenty-four dot plates made for it, each hiding a digit in colours that people with one kind of colour vision difference cannot tell apart, and three control plates that everyone should read. It names a pattern: none seen, likely red-green, likely blue-yellow, or that your screen or settings cannot show the check. It cannot diagnose a colour vision difference or rule one out, because a screen cannot show exact colours and the light in the room changes them, and it gives no score and no strength. If your work, a licence or a course depends on colour vision, or colours have changed for you, an eye-care professional can test it under proper light. Nothing from the check is saved, and nothing in this category carries advertising.

Read first

A guide to plate tests

The kinds of colour vision difference, in plain words

Red-green differences are by far the most common. In the milder forms, some greens look redder or some reds look greener and duller; in the stronger forms, red and green cannot be told apart at all. Blue-yellow differences are rarer and make blue and green, or yellow and pink, hard to tell apart. Seeing no colour at all is rare. Most differences are present from birth and far more common in men; some appear later, from an eye condition, an injury, a medicine or age. The check on this site names only whether a red-green or a blue-yellow pattern is likely, never which kind or how strong.

How a screen check differs from a test with an eye-care professional

An eye-care professional shows printed plates in controlled light, and if the result is unclear can use instruments such as an anomaloscope, where you match two lights, or arrangement tests, where you put coloured caps in order. Those can say which kind of difference you have and how strong it is. A screen cannot: its colours change with the model, the brightness, the display mode and filters such as Night Shift, and the room light changes them again. A screen check can point to a pattern worth asking about. It misses many of the milder differences, and it can be wrong in both directions, most dangerously with a pass.

When to see an eye-care professional

If your work, a licence or a course depends on colour vision; if a child seems to struggle with colours at school; if colours or your sight have changed; or if a plate on any test felt hard. Treat a pattern on a screen as a reason to ask, not as an answer.