My thesis work has focused on the study of a previously undescribed subpopulation of ipRGCs. These cells form an evenly-spaced mosaic and are restricted to the dorsal retina, coding for luminance reflected off the ground. Although they share some morphological similarity with other ipRGCs, I demonstrate this subpopulation has unique central projects to areas of circadian pacemaking, and form the exclusive innervation to the supraoptic nucleus (SON-ipRGCs); a site involved in systemic fluid homeostasis, maternal behavior, and appetite.