Publisher Summary This chapter discusses the chromatographic separation of rod and cone pigments from chicken retinas. Cone cells differ structurally from rod cells in that the visual pigment molecules are in the plasma membrane rather than in intracellular disk membranes. Cones function at higher light intensities than do rods, and multiple cone pigments exist, so that cones are the receptors for color vision. Iodopsin has a chloride binding site that interacts with the retinal chromophore. Chicken retina contains additional visual pigments. These pigments are similar to iodopsin in molecular weight, chromatographic properties, hydroxylamine lability, and rapid regeneration, but they differ in that there is no chloride effect. The chicken retina has been the source of choice for cone pigments used in chemical studies, as relatively large quantities of photoreceptors are needed, and most other slaughterhouse animals have predominantly rod eyes. Chicken retinas differ significantly from other retinas used for visual pigment work. They are mechanically much weaker, so they fragment badly, and this becomes much worse if they are not well chilled during the time before dissection.