The Effects of Blue and White Light on Memory and Cognitive Performance

light, specifically its blue content, influences human cognition, mood, and health. Research shows that the non-image-forming effects of light are initiated by the capture of light in the retina by the intrinsically photosensitive retinal ganglion cells (ipRGCs).1 The melanopsin-expressing ipRGCs, which are known to be maximally sensitive to shortwavelength energy around 480 nm, send signals to the central circadian clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. In return, these signals help control our physiological responses to the environment, such as pupillary constriction, core body temperature, neuroendocrine regulation, and synchronizing daily physiological rhythms to the solar light/dark cycle (also known as circadian photoentrainment).