Figure 1.12 from Sharpe, L. T., Stockman, A., Jägle, H., & Nathans, J. (1999). Opsin genes, cone photopigments, color vision and colorblindness. In K. Gegenfurtner & L. T. Sharpe (Eds.), Color vision: From Genes to Perception (pp. 3-51) Cambridge: Cambridge University Press.
Dichromat confusion lines. Dichromatic lines of constant chromaticity or hue for protanopes (left), deuteranopes (middle), and tritanopes (right), drawn in the Stiles and Burch (1955) 2-deg r(λ), g(λ) chromaticity space (see Chapter 2). The lines have been extrapolated to converge at the confusion or copunctal point, which defines the chromaticity of the missing 2-deg L- (for protanopes), M- (for deuteranopes), or S- (for tritanopes) cone fundamental of Stockman and Sharpe (2000). The spacing of the lines is based on the spectral wavelength discrimination data of protanopes (Pitt, 1935), deuteranopes (Pitt, 1935), and tritanopes (Fischer et al., 1951; Wright, 1952). The neutral points, N, for the equal-energy white, W, and the corresponding confusion lines (dotted lines) are shown.
Fischer, F. P., Bouman, M. A., & Doesschate, t. J. (1951). A case of tritanopy. Documenta Ophthalmologica, 5-6, 73-87.
Pitt, F. H. G. (1935). Characteristics of dichromatic vision. Medical Research Council Special Report Series, No. 200. London: His Majesty's Stationery Office.
Sharpe, L. T., Stockman, A., Jägle, H., & Nathans, J. (1999). Opsin genes, cone photopigments, color vision and colorblindness. In K. Gegenfurtner & L. T. Sharpe (Eds.), Color vision: From Genes to Perception (pp. 3-51) Cambridge: Cambridge University Press.
Stiles, W. S. (1955). Interim report to the Commission Internationale de l'Éclairage Zurich, 1955, on the National Physical Laboratory's investigation of colour-matching (1955) with an appendix by W. S. Stiles & J. M. Burch. Optica Acta, 2, 168-181.
Stockman, A., & Sharpe, L. T. (2000). Spectral sensitivities of the middle- and long-wavelength sensitive cones derived from measurements in observers of known genotype. Vision Research, 40, 1711-1737.
Wright, W. D. (1952). The characteristics of tritanopia. Journal of the Optical Society of America, 42, 509-521.