[Confusion lines in dichromatism using various surface colors]

Confusion lines, convergence points, and neutral points in dichromatism were examined using various surface colors. Confusion lines were obtained from 8 cases of protanopia and 24 cases of deuteranopia by color matching with the surface colors of the Farnsworth-Munsell 100 hue test, then regression analysis was carried out on the cross-points of all confusion lines obtained. Convergence points were obtained and neutral points were also calculated. The convergence point obtained from protanopia using surface colors converged to x = 0.811 and y = 0.189, which is a point near Pitt and Judd's convergence point. The confusion line gradient obtained from deuteranopia was steeper than that of Pitt and Judd's line. The convergence point of deuteranopia was x = 1.959 and y = -0.959. Compared with previous reports, it was in the lower right region. The neutral point of protanopia was in the vicinity of 495 nm and that of deuteranopia in the vicinity of 500 nm. These two values were almost the same as the values in Judd's report. Considering the results mentioned above, the neutral point obtained with surface colors was almost the same as that obtained with spectrum color. From the above results, the convergence point was thought to be different from that obtained using spectrum color. In particular, the difference was significant in deuteranopia.