Is the rhesus protanomalous?

Comparison of rhesus, human trichromat, and human protanomalous subjects were made for measurements of spectral sensitivity involving Landolt ring acuity criteria from 0.11 to 1.11 min-1. At 0.11 min-1, rhesus spectral sensitivity was more similar to that of the normal human trichromats than that of the human protanomalous observers. However, as acuity criterion became finer (thereby involving more central retinal function), rhesus spectral sensitivity became markedly more similar to that of the human protanomalous observers than that of the normal human trichromats.