About one man in twelve and one woman in two hundred sees red and green differently from most people. Many find out late, from a job test or a child who cannot tell the colours in a game. A test at home takes two minutes and tells you whether a proper examination is worth booking. It does not tell you which type you have or how strong it is; an optometrist does that with printed plates and other tests.
Numbers hidden in dots
Each plate is a field of coloured dots. Most people see a number; with red-green difficulty, some plates look empty.
Control plates
Two plates are visible to everyone. If you miss them, the screen or the light is the problem, not your eyes.
A result you can keep
Copy it, or save it in Anpheros Daily on your profile or your child's.
How the test works
- Set your screen up. Brightness high, night mode and colour filters off, no strong sunlight on the screen.
- Look at each plate for a few seconds, from a normal reading distance.
- Tap the number you see, or "I see nothing" if no number stands out. Do not guess from the shape of the dots.
- After eight plates you get your result.
The plates are drawn fresh each time, so you cannot learn the answers, and a child can take the test again in a month without remembering them.
What the result means
- All or nearly all plates read correctly: your colour vision is most likely typical. The test cannot rule out a mild difficulty.
- Several plates empty or misread, control plates correct: a possible red-green difficulty. This is common, usually inherited, and does not get worse. It is worth confirming with an optometrist, who can tell you the type and how it may matter for driving, work or a child's schooling.
- Control plates missed: the test could not run properly on this screen or in this light. Try again with the screen brighter and no colour filter.
The test looks only at red-green difficulties, by far the most common. Blue-yellow difficulties and acquired changes (from some medications, diabetes or eye disease) need an eye examination, not a screen.
For children
From about five years old a child can take the test with a parent naming the numbers they see; before that, children often cannot read numbers reliably. If a child misses several plates, mention it to the paediatrician or an optometrist: knowing early helps at school, where colour is used everywhere, and the child can take the test again on their own profile in Anpheros Daily.
Keep the result
Copy the result at the end, or save it in Anpheros Daily, the free health record app. There it stays with the date, on the right person's profile, and can be shared with a doctor when you choose.
Frequently asked questions
Is this an Ishihara test?
It uses the same principle, numbers hidden in dots whose colours are confusable for red-green deficiency, but the plates are generated by Anpheros, not the original Ishihara plates, and they are drawn on a screen rather than printed. Treat it as a screening, not the clinical test.
Can a screen test be accurate?
Screens differ in colour, brightness and settings, which is why the test includes control plates everyone can see, and why the result is indicative. A clear pattern of missed plates on a well-set screen is a good reason to get examined; a perfect score does not guarantee typical colour vision.
Does colour blindness get worse?
Inherited red-green deficiency is stable for life. Colour vision that changes over months is a different matter and needs an eye doctor.
Can I take it with glasses on?
Yes, and you should, if you normally wear them. Glasses do not change colour perception; blur does.
Is the test free?
Yes, with no account. Saving the result in your health record is free too, in the Basic plan of Anpheros Daily.
Does it work for red-green only?
Yes. The plates are designed for red-green confusion, which covers the great majority of cases. Blue-yellow deficiency is rare and needs different plates and an examination.
