Why can blue light from screens completely reset your internal clock?

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The Science of Circadian Disruption

Blue light is a high-energy, short-wavelength light that penetrates deep into the eye. This spectrum is particularly effective at suppressing the production of melatonin, the vital hormone responsible for signaling to the brain that it is time to sleep. When screens emit this intense light, the body mistakenly perceives it as daylight, causing significant physiological effects:

Suppression of Pineal Gland: Exposure to blue light signals the pineal gland to halt melatonin secretion instantly.
 Shift in Circadian Rhythms: Consistent exposure delays the timing of your internal clock, leading to shifted sleep patterns and reduced sleep quality.
 Alertness Trigger: This light wavelength stimulates the melanopsin-containing retinal ganglion cells, which transmit signals directly to the hypothalamus, the area of the brain that governs biological rhythms.

Practical Strategies for Better Sleep

To mitigate these effects, experts recommend several proven techniques to protect the biological clock. Utilizing 'Night Mode' settings that filter out blue light can shift screen emissions toward warmer, redder tones. Additionally, wearing blue-light blocking glasses during evening hours or simply turning off digital devices at least one hour before bed allows the natural biological processes to proceed undisturbed, ensuring restorative rest and optimal alertness upon waking.