The foundation base of the Nopia color blind wheel illustrates the color deficiencies associated with each condition: Protanopia, Deuteranopia, Tritanopia, and Achromasia
Protanopia (red-green deficiency) is represented by the largest circle. This condition is the most common in color vision deficiency (CVD)
Tritanopia (blue-yellow deficiency) is indicated by the third small circle. This condition is not as prevalent within context of color vision deficiency (CVD)
Deuteranopia (red-green deficiency) is represented by the second largest circle. This condition is similar with protanopia in color vision deficiency (CVD)
The Nopia color blind wheel's indicator depicts the deficiencies linked to each condition
Achromasia (total deficiency) is indicated by the last circle in black to grayscale. This condition is extremely rare in color vision deficiency (CVD)
Different color vision deficiency compared to normal vision