Online color vision deficiency (a.k.a. color blindness) test since 2000.

Important note: all the online tests require Java Plug-in which is installed on most computers. You can easily find out if Java is working on your system.

Color Vision Test V3.12 (Release date: 2009-05-09)

Integrated Test diagnosing all three types of color vision deficiency
Protanopia Test diagnosing protanopia (a.k.a. red blindness)	Deuteranopia Test diagnosing deuteranopia (a.k.a. green blindness)	Tritanopia Test daignosing tritanopia (a.k.a. blue blindnes)

View your test data (Please note that due to the test's international popularity, the time stamp is UTC, not local time).

Test instructions:

1. Click button"Start" to begin the test.
2. Click one of the three small squares which color matches the large test pane above them. Each click is a sample point. The bottom bar shows the total test number and the score quality gauged by margin of error.
3. Repeat step 2 untill achieving satisfactory score quality ("very good" is recommended, "excellent" is the highest quality).
4. Click button "Finish" to see the results.

The quality of the test dependst on the quality of the display device (e.g. CRT).  Tom Niemann's ePaperPress is a good Web site for helping calibrate monitors. 

How to interpret the test results:

All of the reported data are simple, straight forward and self-explanatory statistical parameters except the adjusted score which is the most important number.

Adjusted score, in a nutshell, is the estimated true portion of correct response in terms of percentage. For example, an adjusted score of 80 means it is estimated that 80% of the time the testee truly knows the correct color and the rest (20%) of the time he just guesses. Since there are three choices, a completely color blind person can get 1/3 of his responses right by randomly picking the choices. Therefore correct portion of 33% is translated to an adjusted score of 0.

It is possible to have negative adjusted score. This means the testee's color vision is even worse than complete color blindness. In other words, the wrong colors are more likely to be picked than the correct ones. In reality, the negative adjusted score is usually a result of statistical variation, especially of small sample numbers. The design of this test, due to its uniform image pattern, uniform background and random brightness, does not allow any inherent negative adjusted scores.

The protanopia (red-blind, missing long-wavelength photopigment) and deuteranopia (green-blind,  missing middle-wavelength photopigment) tests are almost the same because the long (red) wavelength photopigment's spectral sensitivity is very close to that of middle (green) wavelength photopigment.  In other words, protanopes and deuteranopes will probably test positive on both tests.

Coming soon: pediaric frienldy version.

Color Vision Test V2.0 (Release date: 2002-07-04)

• Deuteranopia test
• Protanopia test
• Tritanopia test

Test instruction:

Test instruction:

1. Click button"Start"
2. Click the button below the small square which color you believe is closest to that of the main pane.
3. Repeat step 2 as many times as you want (more than ten times preferred).
4. Click button "Finish" to see the results.

Colblindor has a very readable blog explaining Color Vision Test V2.0, especially, from the view of a color deficient person.

Color Vision Test V1.0:

(sorry, this obsolte test suite is no longer available).

These color vision tests are based on the confusion lines.