Blue and red lights chosen to evoke equally large increases in the amplitude of the electro-oculogram (EOG) in the normal human eye were used to test eyes with defective cone function. It was found in five totally color-blind subjects that the response to red light was below the normal range, whereas the response to blue light was within the normal range. The results indicate contribution of both rod and cone mechanisms to the generation of the light-induced response of the normal human EOG.
Elenius V, Aantaa E. Light-Induced Increase in Amplitude of Electro-oculogramEvoked With Blue and Red Lights in Totally Color-Blind and Normal Humans. Arch Ophthalmol. 1973;90(1):60-63. doi:10.1001/archopht.1973.01000050062013