We have shown that with field sizes of 8 degrees or more, protanopes and deuteranopes have trichromatic vision. We propose a full delineation of this large-field trichromacy, and a comparison of large-field trichromacy with small-field dichromacy. We will perform psychophysical studies on protanopes and deuteranopes using fields of either 8 degree or 1 degree visual angle. The specific studies we propose include: color matching, luminosity (by heterochromatic flicker photometry), wavelength discrimination, hue estimation, and threshold additivity.