Protanopes and deuteranopes (red-green dichromats) lack, respectively, long (L) or medium (M) wavelength-sensitive cones because of genetic factors (Neitz & Neitz, 2011).
Age in Years
Protanope Deuteranope Tritonope 30-40 -- -- 3 41-50 2 1 6 51-60 -- 1 5 61-70 2 2 8 Group II
AMLA,
protanope observers and relative luminosity variations
Among the colour blind 20 (1.2%) were
protanopes, 3 (0.2%) were deuteranopes and none were tritanope.
Additionally, the current study complements our previous work (Lillo et al., 2012; Moreira et al., 2012) on dichromats' (
protanopes and deuteranopes) use of BCTs (for a complete description of both studies see Moreira, 2010).
Effect of luminance on color perception of
protanopes. Vision Research, 38, 3397-3401.
The participants were divided into five groups: normals, deuteranomals, deuteranopes, protanomals, and
protanopes. For the response times, assumption of normality was assessed by the Shapiro-Wilk test for each of the nine participant subgroups (four additional subgroups were created by placing anomalous trichromats in severity categories) and found to hold for all signals.
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).
Protanopes have a normal M gene, whereas deuteranopes have a normal L gene.
Protanopes (who lack the long-wavelength-sensitive red cone) have a loss of color vision as profound as that of deuteranopes.
Dichromats lack red pigment gene and those lacking green pigment gene are known as
Protanopes while those lacking blue green pigment are known as Tritanopes (4).
Those with colour vision defects see the spot differently; for example
protanopes usually describe it as blue or dark because their red sensitivity is reduced, and most deuteranopes cannot see the spot at all.
