We report experimental studies of an individual with different types of color vision in his two eyes. The left eye is typically deuteranomalous, with good wavelength discrimination. The right eye is typically deuteranopic, both in its wavelength discrimination and in its color matching functions. Luminosity curves of left and right eyes are indistinguishable, both being within the normal range. Binocular matches show that the colors seen with the dichromatic eye range from “orange” (610 nm) at long wavelengths to “greenish blue” (473 or 474 nm) at short wavelengths. Possible physiological and genetic mechanisms are discussed.