Blue Light & Sleep: How Does Blue Light Affect Sleep?

Many of us have heard from our doctors about the importance of putting our phones down before bed. Yet, 90% of Americans reported using an electronic device in their bedroom within an hour of trying to sleep.[1]

This is an issue because the blue light emitted by our screens can interfere with our natural sleep cycles. While blue-light filtering glasses are all the buzz, there are other ways we can decrease our exposure to blue light sources, particularly, before bed.

What is Blue Light?

Light is a form of electromagnetic radiation, which means that light is a form of energy. The colors we see with our eyes are dependent upon the amount of energy the light contains.  When we look at the rainbow, we can see the entire visible spectrum of light.

Blue light is a part of the visible light spectrum that affects our natural sleep cycle or our circadian rhythms. We have sensors in our eye looking specifically for a blue sky, telling our bodies it is daytime and providing energy and alertness.

example of blue light

Our bodies are powered by circadian rhythm or an internal body clock that regulates our sleep and wakefulness. This 24-hour cycle is set primarily by blue light, predominately found outdoors.  However, electric lighting contains lot of blue light, sending confusing daytime signals to your body.

Is blue light bad for humans?

No, blue light is not bad for humans. In fact, blue light during the day is important for our wellbeing, circadian rhythm, alertness, and cognitive performance.

However, blue light at night can suppress melatonin, a naturally produced hormone critical for sleep and recovery.  In today’s modern society we are continuously exposed to blue-light emitting devices and technologies, sending improper daytime signals to our bodies.  It is important to know the blue light effect on sleep, in terms of quality and circadian rhythm.

Sources of Blue Light

Many of the devices we need and love emit blue wavelength light. Some of these include:

  • Fluorescent lights
  • LED Lights
  • Smartphones, Tablets, & E-Readers
  • Computer Screens
  • TV Screens
  • Gaming Systems

How Does Blue Light Affect Sleep?

A reasonable question to ask is “Why is it bad to sleep with blue lights on?”

During the day, the effects of blue wavelength light are positive but at night, can make falling asleep very tough.  Electric light sources at night can send daytime signals to your body; suppressing melatonin, a sleep hormone, and increasing cortisol, a stress hormone. [2]

These electric sources of light can reduce your sleep quality and make you groggy the next morning. [3]

blue light at night

Over time, the continued use of blue light an hour before bedtime can result in misaligning your circadian rhythm. This can have a negative impact on your health including poor skin, a weakened immune system, or mental health conditions. [4]

How to Manage Blue Light Exposure

You don’t need to block blue light at night entirely, but there are ways you can manage your exposure to it and keep your circadian rhythm in sync.

Limit screen time before bed

Get in a routine or set an alarm that reminds you to turn off your electronics 2 to 3 hours before bedtime.

Dim screen brightness

When using your electronics at night, dim the brightness of your screen or enable “night” mode if your device has it.

Blue light blocking glasses

If you work on a computer or play video games for long periods of time, consider purchasing blue light filtering glasses. They are sold widely online and range in price and quality.

Use circadian lighting solutions

natural light

BIOS Lighting offers advanced LED lighting technology designed to help consumers take back control of their circadian rhythms and health.

For lighting your spaces during the day, explore the SkyBlue A21 LED light bulb or SkyBlue® BR30 LED bulb. They emit specific wavelengths designed to mimic natural, outdoor sunlight.  Dim them down at night to remove all the blue signals, leaving a warm blue free amber color.

For lighting your indoor spaces during the evening, check out the Nightfall A19 LED light bulb for a natural night’s sleep. It reduces the unwanted alerting blue sky signal by 700% to create a tranquil evening environment.

For a more comprehensive circadian lighting solution, the Skyview™ Wellness Table Lamp cycles through 4 different lighting modes: Sunrise, Daytime, Sunset, and Nighttime. Wake up, stay alert, rest, and go to sleep with BIOS SkyBlue®


[1] Gradisar, M., Wolfson, A. R., Harvey, A. G., Hale, L., Rosenberg, R., & Czeisler, C. A. (2013). The sleep and technology use of Americans: findings from the National Sleep Foundation’s 2011 Sleep in America poll. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 9(12), 1291–1299.


[2] Figuiero, MG and Rea, MS. (2010).  The Effects of Red and Blue Lights on Circadian Variations in Cortisol, Alpha Amylase, and Melatonin.  Int J Endocrinol. 2010; doi: 10.1155/829351

[3] Chang, A., Aeschbach, D., Duffy, J. F., & Czeisler, C. A. (2015). Evening use of light-emitting eReaders negatively affects sleep , circadian timing , and next-morning alertness, 112(4). https://doi.org/10.1073/pnas.1418490112

[4] Roenneberg, T., & Merrow, M. (2016). The Circadian Clock and Human Health. Current Biology, 26(10), R432–R443. https://doi.org/10.1016/j.cub.2016.04.011