What is the Origin of Temporal Light Dosing?

This concept is a core tenet of chronotherapy, emerging from the scientific understanding of the Phase Response Curve (PRC), which dictates the circadian system's sensitivity to light at different times. The term emphasizes the importance of timing and quantification in light-based interventions, treating light as a pharmaceutical agent.

What is the Mechanism of Temporal Light Dosing?

The dosing operates by delivering light at the precise moment on the PRC where the SCN is most susceptible to a phase shift. For instance, morning light dosing, rich in blue wavelengths, drives a phase advance by stimulating the intrinsically photosensitive retinal ganglion cells (ipRGCs). This photonic input resets the SCN's molecular clock, thereby shifting the timing of all downstream circadian-controlled events, including the sleep-wake cycle and the nocturnal onset of melatonin secretion.

Temporal Light Dosing ∞ Area

Temporal Light Dosing

Meaning

Temporal Light Dosing is the precise, clinical application of light exposure, defined by its intensity, spectrum, and duration, delivered at specific times of the day to therapeutically modulate the circadian rhythm. This technique is utilized to treat sleep phase disorders, jet lag, and shift work disorder by strategically leveraging light as a powerful zeitgeber to phase-advance or phase-delay the body’s master clock. Correct dosing ensures optimal alignment of hormonal cycles, such as the cortisol and melatonin rhythms.