How Light Affects the Sleep Cycle

We all have our own biological rhythm (specifically, the so-called circadian rhythm), which regulates our activity throughout the day. Just as the day begins at sunrise and ends at sunset, we, too, should maintain such a regular cycle. Ours, however, is defined by quality sleep. 

Night has fallen, darkness reigns outside, and we’re still staring at the bright blue TV screen under the glare of the harsh surrounding lights. This is a classic scene for most of us, but it can have a negative impact on our sleep. And yet, the more light there is, the more alert we become—and artificial light is the most harmful of all.

How does the body prepare for sleep?

Have you ever woken up a minute before your alarm went off? Everyone has an internal clock that regulates their sleep cycle. And light has a significant impact on it. Above all, it affects our retinas. Signals are transmitted through the retina to the brain, influencing chemical processes in the body. These processes cause changes in physiology and behavior.

We experience this phenomenon every evening. The sunlight fades, and melatonin—the hormone that promotes sleep—begins to rise. Our bodies feel tired, our body temperature drops, and we’re ready to go to bed. Conversely, as dawn breaks, fresh rays of sunlight stream in through the window. Melatonin levels drop, our body temperature rises, and other chemical processes prepare us for an active day.

The Dangers of Screens

We must be careful with light—and especially with certain shades of it. Cool yellow and bright blue are among them. We all feel that a clear, cloudless sky boosts our energy and positive mood. A cell phone or TV screen has the same effect on us. Blue significantly blocks the sleep hormone melatonin.

Before going to sleep, it’s important to counteract this effect. And if you still want to watch your favorite show, turn off all the lights around you or dim them to the lowest setting. The warmer the light, the more ideal the environment for sleep. If you have a smart LED bulb, be sure to select a red hue. That’s the best choice for falling asleep.

Thermal Color Scale 

Sleep Patterns and Modern Technology

Since the days when only traditional incandescent bulbs were used, lighting technology has advanced significantly. LED technology has brought energy savings, a wide color spectrum, and a variety of control options. Using a remote control, you can transform harsh blue light into a soothing red—all right from your bed.

Smart homes have taken control a step further. Processes have been automated. Using a cell phone, you can set the exact time when the light will bathe the bedroom in a warm glow, only to wake you up the next morning with a bright light.