Protanopes and deuteranopes (red-green dichromats) lack, respectively, long (L) or medium (M) wavelength-sensitive cones because of genetic factors (Neitz & Neitz, 2011).
(2014) found different selections for real protanopes and real deuteranopes. These values are similar to those found in other works (i.e., see Figure 6 in ref.
There ar those (deuteranopes
) whose cones lack one light-absorbing dominant pigment (in the green range of light waves for most observers under most conditions) and those (protanopes) who lack, instead, another light-wave dominant pigment (in the red range of light waves for most observers under most conditions).
Age in Years Protanope Deuteranope Tritonope 30-40 -- -- -- 41-50 -- -- -- 51-60 1 1 -- 61-70 -- -- -- Sample size calculations were done by using previous prevalence of 39.5% (6).
Out of these 30 subjects, 22 subjects were tritonope, 4 protanope, and 4 deuteranope, which is in agreement with the study published by Sinha A K, Bhatia R et al.
There is one exception: The conspicuity of traffic signals was lower for the recognition criterion than for the detection criterion for deuteranopes. This is because the recognition criterion required identification of whether a stop or go traffic light signal was displayed, and deuteranopes are known to have difficulty recognizing the colors of signal lights (Vingrys & Cole, 1988).
Search conspicuity for the deuteranopes is about 60% of that found for color-normal observers, except for the yellow warning signs, green direction signs, blue parking signs, and speed restriction signs, for which conspicuity did not differ between the two groups of observers.
Distribution of Protanopes and Deuteranopes
Colour Blind Protanopes Deuteranopes
Total Affected 20 (1.2%) 3 (0.19%) 23 (1.4%) Table 3.
The differences are statistically significant, except for normal participants between G and Y signals, for deuteranomals between G and Y signals, for deuteranopes between R and Y signals, for protanomals for Y signals with both R and G signals, and for protanopes for Y signals with both R and G signals.
The deuteranopes showed the greatest increases in response time, 53% for R and 85% for Y, relative to those of normals.
The classification plates are more effective for deuteranopes than protanopes, with a correct classification possible for around 90% of deuteranopes and around 80% of protanopes.
(22) All deuteranopes and 96% of protanopes failed the test.