What is the Origin of Light Dosing?

This term is rooted in chronobiology and phototherapy research, which established the existence of non-visual photoreceptors in the retina that communicate directly with the SCN. The clinical application involves treating circadian rhythm disorders and mood disorders by precisely timing light exposure.

What is the Mechanism of Light Dosing?

The mechanism relies on the melanopsin-containing retinal ganglion cells, which are maximally sensitive to blue-green light, signaling the presence of light to the SCN. Morning exposure to bright, blue-enriched light advances the circadian phase, promoting an earlier cortisol awakening response and melatonin suppression. Conversely, minimizing blue light exposure in the evening prevents phase delay and supports the timely nocturnal rise of melatonin.

Light Dosing

Meaning

The precise, intentional management of an individual’s exposure to specific wavelengths and intensities of light at defined times throughout the 24-hour cycle. This intervention is utilized to entrain or re-synchronize the central circadian pacemaker, the suprachiasmatic nucleus (SCN), which is essential for regulating the diurnal rhythm of key hormones. Optimal light dosing is a non-pharmacological strategy for improving sleep, mood, and metabolic health.