Using red light at night helps to ease the transition into sleep by minimizing disruptions to the circadian rhythm and creating a calming sleep environment 😌
The circadian rhythm is a natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours. This cycle is governed by the suprachiasmatic nucleus (SCN), a tiny region in the brain's hypothalamus, which is influenced by external cues - light being its most potent “zeitgeber” (German for “time-giver”).
The circadian system is most sensitive to shorter-wavelength light, such as blue light. Shorter wavelengths are more effective at influencing the internal clock and promoting wakefulness, and exposure to this light, especially in the morning, helps reset the internal clock and synchronize the circadian rhythm with the external day-night cycle ☀️
Using red light in the evening, on the other hand, is beneficial for maintaining a healthy circadian rhythm. Red light allows individuals to engage in evening activities without disrupting the natural progression towards sleep. By aligning light exposure with the circadian rhythm, individuals can enhance their overall sleep quality and regulate their internal clock ⏰