Color Vision Deficiency (a.k.a. Color Blindness) Tests

1. Click button "=>" at the center of the test panel to begin the test.
2. Look at the test panel consisting of color dots with one of the four shapes (square, circle, triangle and star) embedded. Click the corresponding shape in the choice panel to collect one test point. If you are unable to identify the shape, click the last choice with a question mark.
3. Repeat step 2 until achieving satisfactory score quality ("very good" is recommended, "excellent" is the highest quality) which is displayed on the bottom-left.
4. Click button "=>>" below the choice panels to finish the test and see the results.

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

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 chooses either "do not know" (i.e. the last choice with a question mark) or a shape by guess. Since there are 4 choices, a completely color blind person can get 1/4 of his responses right by randomly choosing among the four shapes. Therefore correct portion of 25% is translated to an adjusted score of 0 if "do not know" is never chosen.

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 (missing long-wavelength photopigment) and deuteranopia (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.

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

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.

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.