Circadian Light

Circadian Light

Articles tagged with "Circadian Light".

Circadian Light Sensitivity: How Different Wavelengths Regulate Melatonin

Tags: Circadian Light, Melatonin Regulation, Light Wavelengths, Spectral Sensitivity

October 22, 2025

How Do Different Light Wavelengths Affect Melatonin Production?

Different wavelengths of light have dramatically different effects on melatonin regulation, with blue light being up to 5 times more effective than green light at suppressing melatonin production. This comprehensive spectral analysis reveals that human circadian photoreception follows a distinct sensitivity curve, peaking in the blue range (460-480nm) and declining sharply toward longer wavelengths. The research demonstrates that the circadian system uses a specialized light-detection pathway that differs significantly from vision, explaining why the color and timing of light exposure are crucial for healthy sleep-wake cycles.

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Light-Sensing Cells in Your Eyes Control Sleep: Beyond Vision

Tags: Photosensitive Cells, Circadian Light, Retinal Ganglion Cells, Non-Visual Light

October 22, 2025

How Do Your Eyes Control Sleep and Circadian Rhythms Beyond Vision?

Through intrinsically photosensitive retinal ganglion cells (ipRGCs), specialized cells in your retina that detect light specifically for circadian regulation, not vision. This groundbreaking discovery revealed that your eyes contain a “third” light-sensing system, separate from rods and cones used for vision, that directly communicates with your brain’s circadian clock. These cells contain melanopsin, a unique light-sensitive protein that responds primarily to blue light and sends timing information to the suprachiasmatic nucleus to synchronize your biological rhythms with the day-night cycle.

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