What is Circadian Lighting And Why It’s Important To Understand Light?

Light is like a double-edged sword. It can improve energy levels, mood, performance,  sleep and body regeneration by enhancing robust circadian rhythms. In contrast, light exposure at the wrong time can delay sleep onset by inhibiting the secretion of the regenerative hormone melatonin at night. 

Circadian Rhythm Sensitivity To Light

For millions of years, humans evolved under natural light, and all physiological processes have been adapted to different light frequencies. Our eyes are supposed to see the regenerative morning light at around 40 LUX (LUX is a metric for light intensity) and bright natural light during the day at 100 000 – 130 000 LUX. Exposure to bright natural light has a profound effect on energy metabolism and cognitive brain function. Hormones and neurotransmitter exhibit a light-dependent pulsatile release according to the organisms circadian rhythm. 


The jetlag we suffer after a transatlantic flight is nothing else but a circadian mismatch in which hormones and neurochemicals are still released according to departure time zone and yet not adapted to destination time. The consequences are symptoms like insomnia, fatigue, cravings at an abnormal time of the day, headaches and many more.


The exposure to circadian time cues efficiently alleviates these symptoms and light is one of them If you want to explore more information about the importance of circadian rhythms and get deeper insights into the bondage between human and nature and improve your sleep pattern, I would recommend reading my book Sleep Timer


Circadian rhythms are the cornerstone of a healthy body and mind and if you want to optimize your lifestyle or the environment start from there.



Circadian Lighting For Home

Unfortunately, in today’s reality, it is almost impossible to spend much time in daylight outside, which makes it necessary to improve the artificial light conditions of our indoor environments. Adapting the indoor illumination to our biological needs can have a profound impact on our daily wellbeing and sleep at night. Daylight exposure is critical for robust circadian rhythms which indirectly impacts sleep onset at night. 

A good baseline to get the beneficial effects of daylight is around  10 000 LUX. As you may notice from the list below, indoor illumination has much lower brightness than natural sunlight even on a cloudy day.

Examples of Light Intensity Levels

  • Bright sunlight; 120 000 LUX
  • Bright sunlight behind a window; 70 000 LUX
  • A partly sunny, partly cloudy day; 10 000 – 20 500 LUX
  • Typical overcast day; 1000 – 1500 LUX
  • Office lighting with workplace next to the window; 1000 LUX 
  • Supermarket lighting; 750 LUX
  • Normal office light; 500 LUX
  • Childcare centre; 500 LUX
  • Gymnasium; 200 – 500; LUX
  • Sunset and sunrise; 40 – 400 LUX
  • Street Lights; 320 LUX
  • School classroom, university illumination; 250 LUX
  • Home lighting; 150 – 200 LUX depending on the light source
  • Working areas which do not imply visual tasks; 150 LUX
  • Candle Light; 50 LUX
  • Twilight; 10 LUX
  • Starlight; less than 1 LUX
  • Full moon at clear night; 0.27 LUX

Circadian Rhythm Light Bulbs

If exposure to natural light is not possible, particularly during the winter months, consider using daylight simulators in the morning. The daylight simulators emit bright light at 10 000 LUX. Install the dawn simulator, (so-called circadian lighting) in rooms where you spend some time in the morning, such as the bathroom or kitchen.

This way, the light exposure happens by default. Ten minutes in bright light are enough to enhance the amplitude of circadian rhythms. If you have insomnia issues, try to get as much natural light as possible during the day.

On the other hand, a light intensity of only 10 LUX at night can interrupt sleep. Therefore you shall avoid blue light exposure in the evening or use the blue light blocking glasses. 


Here are my top 4 recommended products that can significantly improve the light in your home or workspace environment during the day.

Tools to improve your daylight environment:

  • Light Therapy Lamp, Sunrise and Sunset Settings, 12000 Lux Bright Light Therapy, UV Free Full Spectrum Sunlight Lamp with Alarm,1-40 Level Adjustabl Brightness, 5 Time Options for Home/Office Use

  • Circadian Optics Lumos 2.0 Light Therapy Lamp | As Seen On Shark Tank | 10,000 LUX Ultra Bright LED | Full Spectrum UV Free | Adjustable Light Panel | Turn On Your Day

  • Light Therapy Lamp, Miroco LED Bright White Therapy Light - UV Free 10000 Lux Brightness, Timer Function, Touch Control, Standing Bracket, for Home/Office Use

  • REPTI ZOO Reptile Full Spectrum UVA + UVB Sun Lamp Self-Ballasted Vapor Basking Spot Lamp/Bulb/Light for Reptile and Amphibian Use


Tools to improve your evening light environment:

Install free software on all screens:  and consider buying effective blue light blocking glasses for sleep.

If you want much more in-depth info on how to choose effective blue light blocking glasses, then you should take a moment and read this article.


How To Reset Your Body Clock and Sleep Better?

What is Body Clock (Circadian Clock)?

Today, more and more, our lives are being influenced by modern technology and especially high-frequency blue light. We are living in social jet lag, and our body clock (circadian rhythm) continuously disrupted – this has a lasting influence on our biology.

There is more and more scientific evidence that shows the connection between current living conditions; they changed the circadian rhythm and the high number of chronic and degenerative diseases. Thousands of people in modern societies have chronic insomnia, metabolic, cardiovascular, and neurodegenerative disease. These numbers are increasing exponentially every year alongside with the advances in technology and science in medicine.

Circadian Rhythms And Sleep Deprivation?

First, let’s see the most typical example of a circadian cycle disruption – it’s jet lag. Most of us have experienced jet lag at some point in life. When we are changing time zones – the further your destination is from your home, the more you will feel it, our bodies are confused with the rapid changes in the environment. It usually takes a few days to the new time zone.

During those few days, we typically have disturbed sleep cycles – insomnia. Waking up at night and crushing during the day, excessive sleepiness, difficulty concentrating and functioning at your usual level, stomach problems, headaches and mood changes. These symptoms are a classic example of a circadian rhythm disruption.

Another excellent example of circadian cycle disruption is watching TV before going to sleep or checking your computer and mobile devices. You are getting exposed to the blue light frequencies at night, and your circadian clock receives the signal that its daytime when it’s not.

Your body will react by not releasing the night hormone Melatonin, and you will not get sufficient sleep and repair, which will reflect itself in a lack of energy in the morning and during the day.

Instead of fixing the problem, most people start making excuses that they are “night owls” or “early birds”, the while disrupting their biology and creating a circadian mismatch. If you have an ongoing lack of sleep, sleep disorder or sleep deprivation symptoms, and want to know how to sleep better, you must identify the factors that cause your insomnia.


The best sleep aid is getting a better understanding of the Circadian Rhythm!

Invest 2 minutes of your time and for FREE Sleep Questionnaire. Analyze your sleep pattern and identify the factors in your daily routine and environment, which will help you to resolve insomnia and reinstall healthy restorative sleep. You get an ultimate answer on how to sleep better and ways to improve your Circadian Rhythm.


Circadian Rhythm Artificial Light.

One more important factor that influences your sleep is light. Did you know that to get a good night sleep you must prepare your sleep routine in the morning?

If you are not getting adequate sunlight frequencies in the morning, the release of all hormones related to arousal and alertness are disturbed. You will need an extra shot of coffee to keep going. Getting exposed to the right light frequencies in the morning is crucial for setting up your timing system.


How Does a Circadian Rhythm Affect Our Body Temperature?

It’s not only light that tells our biological clocks it’s time for bed. The temperature also plays a significant role in this process.

It’s not the clock which is keeping the time; it’s your body.


As the clock approaches wakefulness, our circadian system heats the body. When its time for bed, the circadian system lowers our internal temperature and its nothing to do with the room temperature you are sleeping in.

The little changes in body temperature are sending a signal to the cells and synchronise internal clock and body time for the necessary physiological processes.
There may be a time in the future when the temperature is used to treat circadian sleep disorders, as much as light therapy and melatonin are used today.

Together with light and temperature, the food intake has a significant impact on circadian cycles. Scientists discovered that pigments in our eye and skin could scan time by receiving different light frequencies generated by earth rotation and its geophysical consequences. Our bodies evolved during evolution by the accumulation of energy from food produced by the cyclical movements of earth rotation and changes of seasons.

Circadian Rhythm And Food Supply.

In our globalised world, food availability is abundant, and seasons do not exist anymore because of scientific and technical advances. There were no bananas in December in Alaska, Russia or Scandinavia but yet the human race thrived in the northern latitudes. Food availability for all life forms, including humans was based on the changes of seasons with their different light cycles for millions of years.

The question is, what happens if we distance ourselves from the natural circadian cycles?

How Do Circadian Cycles Work?

Our brains can be easily fooled by all kinds of cultural beliefs, diet dogmas, and eating habits, which give you a sense of identity. But our body is always trying to keep time thanks to the integrated circadian system.

Each cell and each organ system reacts cyclically to the light and dark cycles in a particular manner. If it gets confused by artificial light during the night or specific food which is not available under natural condition during a specific season, obesity and type 2 diabetes increase exponentially.

Circadian cycles are the reality of how evolution intended us to be. There is a certain amount of time and a certain amount of energy in life. If your energy system is failing before time is over, you are living a vegetative life!

Importance of Circadian Rhythm?

We must remember that circadian rhythm is not only managing sleep and wakefulness. It also controls everything from energy metabolism, physical performance, vitality, the mood, psychological health, sleep cycles in all cells and organs of the body.

The circadian rhythm determines how we experience life. We can experience life with full energy and confront all situations, and challenges with all our power or we experienced life fatigued and burned out. We all know how a day like this looks like.

So the quality of your life and your health and resilience is highly related to that circadian rhythm.

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