In 1923, scientists observed blind mice responding to light.

"Blind Mice", Keeler C. (1928)

retina layers liberlight

The blind mice's light reflex suggested the existence of a new photoreceptor in the ganglion cell layer of the retina.

This photoreceptor was found to contain the photopigment melanopsin, with peak absorption in the blue light range.

"A Novel Human Opsin in the Inner Retina", Provencio et. al. (2000)


These cells, known as intrinsically photosensitive retinal ganglion cells (ipRGCs), play a major role in synchronizing circadian rhythms to a 24 hour light/dark cycle.


As the amount of blue light in the sky changes throughout the day....


... the human brain responds to the change in blue light.


More blue makes you alert.


Less blue helps you sleep.


An abundance of case studies and peer-reviewed articles show that this naturally occurring phenomenon can be mimicked by tunable lighting products.