• VISUAL ACUITY: A person who has sufficient visual acuity should see the number twelve in the circle on the left whether or not they have normal color vision. This first test is used to explain the procedure of the test to a subject.






• COLOR BLINDNESS: A person with normal color vision sees a number seven in the circle on the left. Those who are color blind decode this only with difficulty, usually do not see any number at all.










• RED-GREEN COLORBLINDNESS: People with red-green color blindness see either a three or nothing at all. Those with normal color vision see an 8.




• PROTANOPIA & DEUTERANOPIA
Those with normal vision see the number thirty-five in the circle above. A person with protanopia sees only he number five. A person with deuteranopia sees the number three. People who are partially color blind will see both numbers but one more distinctly than the other. There are two major forms of red/green color blindness. Normal or slightly color blind persons can see a "35" in this illustration. Persons strongly affected by protan color blindness will see only a "5", while those with strong deuteran color blindness will see only the "3."