Blog, Science

The Neuroscience of Sleep & Computer Screens

This is a recovered article from 2015 featuring neuroscience professor Dr. Robert McDonald on the topic of sleep and computer screens.

The United Nations declared 2015 the International Year of Light and Light-Based Technologies.

This year they commemorate the technologies that use light and harness light such as Fiber Optic Cables, Light Bulbs, LEDs, Lasers; the list goes on.

These technologies enhance our lives in numerous ways and the science of light continues to aid everything from the Internet & computers to sanitation & medical care.

But at some point, we must ask the question…

Are all these lights necessarily good for us?

As advances in technology continue, it is important that we recognize what parts are harmful and amend them as development continues.

Could we keep the good & remove the bad?

Computer technologies greatly enhance well-being, but current science is suggesting that the LED screens are actually unfavorable to our internal body systems.

Have you ever googled something before bed and ended up staying awake staring at your screen for hours?

Be honest.

At nighttime, the bright light of phones and computer screens disturbs the natural day/night cycle that our bodies need for optimal health.

Dr. Robert McDonald of the University of Lethbridge Neuroscience Department has been studying the circadian rhythms in animals and humans for the past 20 years.

I asked him to explain how the circadian system affects our health and he said that most modern devices disturb these delicate internal rhythms.

“The earth is like a spinning clock because of its precisely timed rotation on an axis and its relationship to the sun,”

“Almost every organism on earth has been shaped by the day and night cycle… So via evolutionary processes we and other organisms have been equipped with an internal clock found deep in the brain that is set by the light/dark cycle. Unfortunately, this ancient clock was not designed for all the artificial environments we experience in modern life which put strain on the circadian system.”

The word circadian comes from Latin and roughly translates to ‘about the day’.

The rhythm is roughly 24 hours and 20 minutes in length and is reset every single day by exposure to the morning sunlight.

The circadian system is the master clock that regulates and influences a ton bodily functions.

Important things such as:

  • Sleep/wake cycles
  • Bowel movements
  • Blood pressure
  • Body temperature
  • Mental alertness
  • Muscle strength
  • Cell regeneration
  • Hormone regulation

The circadian rhythm is also closely tied to other ‘peripheral oscillators’, which include regulation of the liver, heart, stomach, esophagus, lungs, pancreas and spleen…

Nighttime exposure to a bright light resets our internal clock at the wrong time and results in what Dr. McDonald calls ‘poor circadian health’.

“There are a wide range of effects on the brain and body when your circadian clock gets reset when it isn’t supposed to get reset.”  

Circadian reset can happen when our eyes absorb a specific wavelength of blue light.

The blue color of the sky seems to help remind our body that it’s daytime.

Unfortunately, the light from most LEDs and fluorescent light bulbs contain a lot of this blue wavelength.

Lightbulbs, phones, and computers can trick our body into thinking it’s daytime, even when it’s not…

Current research is outlining a link between circadian health and some conditions such as cancer, obesity, Alzheimer’s disease and dementia…

Fortunately, it is relatively easy to develop healthy circadian habits. Here are some simple solutions that will help balance an upset circadian system.

5 Things you can do to improve your Circadian Rhythm

1. Be regular in your eating and sleeping habits.

Go to bed and eat meals at the same time each day. This way we introduce a consistent rhythm to many of our ‘peripheral’ bodily systems.

2. Bring the lights down at night.

If you must get up to use the bathroom use a dim nightlight to navigate.

3. Use a Non-LED alarm clock.

Using a phone may be convenient but staring at the screen before bed will upset the delicate circadian rhythm, the same is true of LED radio alarm clocks.

4. Use a sleep mask.

This will greatly improve the quality of sleep by guaranteeing total darkness until morning.

5. Download Computer Programs.

Programs such as f.lux will automatically dim the screen at night time and brighten it again when the sun rises. This method avoids a circadian reset even if you’re using the computer after dusk – a very handy tool for night owls. You can find similar programs for Smartphones.


As we move forward into the technological age we must be attentive to the fact that these technologies can cause us harm. We must learn to amend new technologies as they advance in order to acquire all of the benefits and negate the negative consequences.

By being aware of our own biology and by adapting our technology so that it works with our biological systems rather than against them – together we can develop a healthy, sustainable future.

Thanks for reading