1960 12 Feb. 418/1 His deuteranope and protanope showed virtually identical foveal thresholds,..in excellent agreement with our (photopically determined) identity of this section for all subjects at all brightness levels.
1997 12 556 Stimulation of photopically sensitive photoreceptors (i.e., cones) is sufficient to reset the endogenous circadian melatonin rhythm.