Online Ishihara test for color blindness
This online Ishihara color blindness test is a simple method to diagnose the existence of red-green deficiency.
Red-green deficiency means having problems distinguishing reds and greens and is by far the most common form of color vision deficiency.
This test was originally designed by Dr Shinobu Ishihara in 1917 and this tool has all 38 Ishihara plates of which only 24 will be displayed each time randomly. Each plate contains a circle of dots appearing randomized in color and size. Within the pattern are dots which form a number or a colored line visible to those with normal color vision and invisible, or difficult to see, for those with a red-green color vision defect.
To pass each test you must identify the hidden number or line. At any time you can reveal the answer and at the end of the test you will see the test results.
If you suffer from red-weakness (protanomaly), you will have some difficulty to see the color red.
If you suffer from green-weakness (deuteranomaly), you will have some difficulty to see the color green.
If you suffer from red-blindness (protanopia), you are unable to see the color red.
If you suffer from green-blindness (deuteranopia), you are unable to see the color green.