Thirty-two markedly color-blind subjects were given the Ishihara, Holmgren, and Nagel tests of color vision. In addition, each was given a test series of forty-two pairs of spectral colors at equal and known relatively unequal intensities by means of a spectrometer and spectrophotometer.
Proceedings of the Iowa Academy of Science
©1935 Iowa Academy of Science, Inc.
Benedict, A. A.
"A Further Study of Color Discrimination of Color-Blind Subjects,"
Proceedings of the Iowa Academy of Science, 42(1), 151-152.
Available at: https://scholarworks.uni.edu/pias/vol42/iss1/61