How does Blue Light Affect Sleep [5 Facts on Blue Light and Sleep]

Blue light (such as that emitted by electronic devices) affects sleep the most because it influences melatonin production and circadian rhythms Humans used to depend on the natural cycle of sunlight and darkness for our circadian rhythm.

The innovation of artificial lights increased human productivity and economic growth.

At the same time, it disrupted our internal biological rhythms, becoming a major source of modern sleep problems. A group of cells called the suprachiasmatic nucleus (SCN) controls the circadian rhythm. When light enters the eye, it hits the surface of the light-sensitive retina, which tells the brain what “time” it is.

If the retina continues to detect light at night, the circadian rhythm goes haywire. Without melatonin, your body continues to feel alert, making restful shuteye elusive.

In contrast, when you’re in the dark, your melatonin production increases, making you feel drowsy. Cortisol, the hormone that activates the fight-or-flight response and regulates wakefulness also decreases, allowing your body to relax and prepare for sleep.

That’s because melanopsin, the photopigment that helps eye cells analyze brightness in the retina, is especially sensitive to shorter, cooler wavelengths like blue light. Use blackout curtains or rolling shutters to block the entry of unnecessary light.

Switch to a low-power, warm color lamp in the afternoon to help your body wind down. When you're ready to sleep, turn off the lights and listen to a podcast or audiobook if you’re still not feeling tired.

Aside from the disruptive blue light from screens, the constant notifications will also keep your alertness and stress levels high. You could exchange pre-sleep screen time for meditation to lower your stress levels and lull yourself to sleep.