Blue light (wavelengths ~450–495 nm) is the portion of the visible spectrum that most strongly affects the circadian system. Photoreceptors in the retina (particularly melanopsin-containing retinal ganglion cells) are most sensitive to blue light.
Key Effects
- •Melatonin suppression — blue light at night blocks the natural shutdown sequence
- •SCN activation — signals "daytime" to the master clock
- •Digital caffeine — screens at 11 PM act as a "Force Quit" for sleep architecture
- •Morning benefit — blue light in the AM helps set the circadian timer
In ONDA Life
The Blue Light Firewall protocol: use 100% blue-blocking glasses or "Red Mode" on all devices after sunset. This allows the natural shutdown sequence to initialize.