Blue Light, The Outdoors & Sunlight

As you step outdoors into the sunlight, the human eye is exposed instantly to several visible and invisible light spectrum’s. Blue light and UV light is the most known of these spectrums; they enter our body through the eyes and skin. Initiating chemical reactions in our bodies both inside and outside. A well-known example from UV light is sunburn.Sunlight Outdoors On The Beach. Sunlight & Blue LightSunlight is part of the human race and has been for millions of years, like most animals on planet Earth. It plays an essential role in our survivability as well as being a major contributing factor in the global ecosystem. Sunlight synchronises human and animal sleep cycles known as the circadian rhythm. It’s linked to every part of us, our metabolism, alertness even our mood and mental state. Have you had a stressful day? A short walk in the park or spending time outdoors can completely change how you think and feel, and this is partly due to sunlight.

Blue Light, Sunlight & The Light Spectrum

Many of us do not realise the light emitted by our sun has all the colours of the rainbow. Each colour has a different amount of energy and capability to impact us as humans. Sunlight contains a range of colours, red, orange, yellow, green and blue light, each of these with their specific energy and wavelength (called electromagnetic radiation). When we combine all these colours, we get “sunlight” or “white light”.

Sunlight, The Outdoors, Visible and Invisible Light

Science has proven that the colour we see (or cannot see) links to the wavelength, and this is linked to the amount of energy each colour contains. Long wavelengths, such as those found in the colour Red, has less energy while Blue’s which have shorter wavelengths have more energy. So while we are all cautious about UV light and its damaging effects on our skin and eyes, it sits back to back with Blue Light.

We hope this article clears up where Blue Light sits on the light spectrum. If you want to read more about the damaging effects of blue light, please follow this link: Is Blue Light Dangerous.

Blue Light Blocking Glasses & Sleep

Before the invention of light bulbs, the human circadian rhythm was entirely in sync with the sun because night time light disruption was minimal. At night, exposure to devices emitting blue light is harmful to sleep and the circadian rhythm (the body’s biological clock). Research has proven that Blue Light prevents body temperature from dropping during the night. A slowly decreasing body temperature is a critical process to which the body progresses into the stage of sleep. Blue light keeps the body temperature elevated at day time levels.

Girl unable to sleep at 4am

Studies show that exposure to blue light, even when dim, can suppress the creation of melatonin. This hormone assists in controlling our circadian rhythms. A minuscule eight lux, the level of brightness well exceeded by desk and table lamps, and about twice that of a night light cause disruptions. Light from fluorescent bulbs and LED lights will also produce the same effect.


Blue Light, Sleep & Melatonin

The pineal gland in the brain is responsible for releasing melatonin, and it does so for a few hours before you start feeling tired. Melatonin level reaches its peak in the middle of the night.

Falling Asleep On The Lounge

Reading on a blue light-emitting device like a tablet instead of a printed book at night will take you longer to fall asleep due to the lack of melatonin produced. Essentially, blue light is a stimulant which sends a signal to your brain, tricking it into believing its day time, and you should be awake. Research has identified that people exposed to blue light at night tend to have less REM sleep; this is when when dreams occur. Less REM sleep results in tiredness in the morning, even after a full eight hours of shuteye.


Stephen Lockley, a Harvard sleep researcher, stated that light at night is part of the reason so many people don’t get enough sleep. The idea that blue light is so problematic is that it has a short wavelength that affects levels of melatonin more than any other wavelength does.

Dr Charles Czeisler of Harvard Medical School identified in 1981 that daylight is the mechanism that keeps a person awake. The outside world runs our sleep schedule, so it makes sense that less blue light at night, can help regulate your biological clock.

Wearing blue light blocking glasses at night will contribute to the elimination of sleep and circadian rhythm issues by preventing blue light from reaching your retinas.