Color Blindness Test by Dr Shinobu Ishihara

• Posted by Daniel Flück on March 15th, 2006 filed in Tests

The Ishihara Color Blindness test - named after a Japanese Professor at the University of Tokyo - is the most well known tool to test for red-green color blindness. Mr Ishihara developed this test almost 100 years ago. It was first published in 1917 and is used since then to check if someone is suffering from protanopia or deuteranopia, the two different kinds of red-green color vision deficiencies.

A collection of 38 plates filled with colored dots build the base of this test. The dots are colored in different shades of a color and a number or a line is hidden inside with different shades of an other color. But enough theory, take the color blindness test by Mr Ishihara yourself and be surprised (or not) of the result.

The above link showes the so called small test. The small test consists of 24 different plates (or cards) and the large test of 38. The plates follow a setup of four different test designs:

1. Transformation plates - anomalous colour observers give different responses to colour normal observers. [Plates 2-7]
2. Disappearing digit (Vanishing) plates - only the normal observer is meant to recognize the coloured pattern. [Plates 9-13]
3. Hidden digit plates - only the anomalous observer should see the pattern. [Plates 14-15]
4. Qualitative plates - intended to classify protan from deutan and mild from severe anomalous colour perception. [Plates 16-23]

Ishihara Plate

It has to be mentioned, that tests like this one are never 100% accuarte. This is due to the two following facts: First of all, every computer monitor has its own color correction. So it never can be guaranteed that the seen colors are really the colors which should be seen. This can falsify the results. And second, easily put there can always be some false positives. This test can therefore not be considered as a medical test for color blindness.

Now let’s have a look at the outcomes. I will show you my results and you can, if you like, compare them with your own ones:

• CARD 1: 12. Of course, everybody should see that.
• CARD 2: 3 with a slight shade of an 8.
• CARD 3: A very confuse 29.
• CARD 4: Some dot clusters, that’s all.
• CARD 5: A slight circle at the top.
• CARD 6: Some dots here, some there.
• CARD 7: Dots everywhere.
• CARD 8: Nothing. I mean, I can see the big circle full of little colored circles, but that’s all.
• CARD 9: Nothing.
• CARD 10: Nothing.
• CARD 11: Nothing.
• CARD 12: Nothing.
• CARD 13: Nothing.
• CARD 14: Some lines and clusters but no number.
• CARD 15: More lines and dot clusters.
• CARD 16: I would say a 6 on the righthand side.
• CARD 17: 2, righthand side.
• CARD 18: A blue (?) line more at the bottom of the circle.
• CARD 19: Two crosses. One on the left and the other on the right side of the circle.
• CARD 20: Many colorful dots.
• CARD 21: More colors and more dots.
• CARD 22: Some kind of inner circle with three gaps.
• CARD 23: There is a line, but it has huge gaps in between.
• CARD 24: I can see that one…

If I try to make a conclusion out of my views I would say I am suffering something between strong protanomalia, protanopia and complete color blindness. Yes, I knew it before and I know it even better now: I am colorblind. But at least I could spot the first and the last plate easily.

Further readings:
Ishihara Color Blindness Test at Wikipedia
The Ishihara Color Vision Test
Ishihara Test for Color Blindness

Direct link to The Color Blindness Test by Mr Ishihara.