Last Updated: September 4, 2020

Before humanity invented the electric light, our ancestors maximized the benefits of daytime natural light to work and interact, and used the night to really sleep. The observation of the 24-hour solar day facilitated the synchronization of biological and behavioral wellbeing with the animal and plant forms.

With the dawn of electricity, however, humanity has turned the routine upside down and blurred the difference between day and night. We now stay awake during the night and sleep during the day! We have also created dark office spaces where we install artificial light to help us find our way around!


Here’s the thing!

We are supposed to spend a third of the day sleeping, and the rest of it staying awake. That adds up to a third of our lives we spend sleeping and the remaining two-thirds, staying away from our beds.

Sadly, though, we have altered this 24-hour cycle for productive and entertainment reasons. The adjustment has also tweaked our brains to associate light with happiness, joy, and everything positive about life, except that we contrast it with everything we hate about darkness. We associate darkness with fear, death, ignorance, and all that is bad in our existence. To counter the evil of darkness, we now import the electric light inside our bedrooms where we have it switched on throughout the night!

Of course, this is very bad for health, productivity, and children in the 21st Century. Generation Alpha and Z kids in urban dwellings should play and indulge in life fulfilments that come with visible light and true sleep. These should be free from distractions such as extreme noise, extreme temperature, and electromagnetic emissions from electronics.


Sources of natural and artificial light and darkness:

Daytime natural light is given to us through the sun, fire, animals, and plants. The bio-luminescence emissions from the fire-fly, jellyfish, and plant forms such as mushrooms, are good examples of animal and plant light. Natural darkness is only achieved at night when the sun has set.

On the other hand, artificial light is man-made. The electric light in the form of the bulb is the most common type of artificial light. Other sources of artificial light include the smartphone, computers, neon signs, etc. Artificial darkness is achieved when we create homes and office spaces detached from natural light.


Benefits of natural light and darkness

children playing outdoors under natural light
Children should make use of natural light during the day, and sleep at night under natural darkness. (Photo by Alfred Amuno)

Light makes no sense unless it happens during the day, and likewise, darkness makes no sense unless it happens at night when we are sound asleep, and for very healthy reasons.


1. Natural darkness for Melatonin and Growth Hormones

The day and night cycle stretches for 24 hours and is closely linked to the circadian rhythm – the internal human body clock. The circadian rhythm synchronizes the right sleep at night and alertness during the day, to facilitate our mental and physical wellbeing.

Darkness is given to us at night so that our body parts can relax, and allow important chemical reactions to take place.

The brain releases the melatonin and human growth hormone (HGH) during the night to optimize sleep and body growth.

  • Melatonin is released by the pineal gland to regulate the sleep-wake cycle and make the body feel sleepy. The melatonin hormone, which is also referred to as the ‘Dracula of hormones’ is only released in the presence of natural darkness at night.

It is also a powerful antioxidant known to neutralize skin aging.

melatonin production, together with topically applied exogenous melatonin or metabolites can be expected to represent one of the most potent antioxidative defense systems against UV-induced skin aging.

Melatonin and human skin aging

Continued use of artificial light in the night interferes with the activities of melatonin while the opposite is true.

Create optimal conditions for it to do its job by keeping the lights low before bed. Stop using your computer, smartphone or tablet—the blue and green light from these devices can neutralize melatonin’s effects. 

Luis F. Buenaver, Ph.D., C.B.S.M.
  • The Human Growth Hormone (HGH) is a protein released by the pituitary gland into the bloodstream to help the body grow in height and weight. This is important for children wishing to reach growth milestones.

The hormone also facilitates body metabolism, repair of broken cells, cell reproduction, and just like Melatonin, can speed up the healing process and slow down aging.  The hormone is also released at night, in the course of sufficient and quality sleep.


2. Natural light for positivity and well being

The benefits of natural light are becoming even more evident today because of the effects caused by over-reliance on artificial light.

A case in point is the lack of natural light during fall and winter, which is known to increase depression, irritability and suicidal thoughts, in what is known as Seasonal Affective Disorder (SDA).

Seasonal affective disorder, which is also called as winter depression or winter blues, is mood disorder in which persons with normal mental health throughout most of the year will show depressive symptoms in the winter or, less commonly, in the summer. Serotonin is an important endogenous neurotransmitter that also acts as a neuromodulator. The least invasive, natural, and researched treatment of the seasonal affective disorder is natural or otherwise, is light therapy. Negative air ionization, which acts by liberating charged particles on the sleep environment, has also become effective in the treatment of the seasonal affective disorder.

Role of serotonin in seasonal affective disorder

Sufficient exposure to natural light is known to increase the amount of serotonin in the body, which in turn leads to a better mood and an increased sense of happiness.

Also called the ‘happy chemical’, serotonin is a neurotransmitter and a hormone to an extent, which is resident in the brain and the stomach. It is tasked to transmit signals between brain cells to regulate the human mood, anxiety, and happiness. Imbalances of serotonin levels may also impact sexual performance, sleep, and bone density.

While Serotonin is also derived from a healthy diet it is more beneficial when received through exposure to natural light and sleep.


3. Natural light for learning and productivity

Research shows how exposure to natural light facilitates effective learning in the classroom and productivity in the workplace.

Natural light in the classroom – with open windows, enhances mental performance. On the other hand, artificial lighting in the classroom can lead to depression, anxiety, and failure by learners to focus.

Research on that field has shown that the correct function of circadian rhythms release amongst other hormones, hormones that are responsible for the improvement of the “immediate memory between ten and twelve o’clock in the morning time” 5 , therefore contributes as a positive factor in the learning procedure of students during the school hours. From six in the evening to midnight the hormones that are released are responsible for the “long term memory being at its best so there is a better window of time for studying school work.” 6

Natural light in learning environments

The same can be said of modern open office spaces that are progressively relying on artificial light.

In a recent US and Canada study by Future workplace entitled The Employee Experience, it was observed

natural light and views of the outdoors were their most important office perks, ranking higher than onsite cafeterias, fitness centers, medical care and childcare.


5. Benefits of natural light and darkness for overall health & wellbeing

When we stay awake at night and sleep during the day, we are disrupting the natural functions of melatonin, growth hormone, and serotonin. While it is true we don’t all have identical circadian rhythms, it is important though we all receive the recommended number of sleep night, and indulge in daytime natural light. Luck of sleep at night leaves us dizzy and fatigued during the day and if this continues for days, weeks, and months, our bodies degenerate into a circadian disorder cycle.

Symptoms of the circadian disturbance may include,

  • sleeping at work
  • poor sleep at night
  • fatigue
  • depression
  • anxiety
  • jet lag
  • poor critical thinking
  • reduced productivity
  • poor executive function skills
  • poor focus
  • workplace accidents and errors
  • road accidents

When we sleep for fewer hours during the night and keep napping during the day, our bodies are denied the opportunity to grow well and repair body cells the natural way.

Below is a list of the benefits of natural light and darkness for overall health and well-being:

  • Natural light is great for vitamin D
  • wards of depression
  • reduces the effects of related to artificial light
  • skin and overall fast aging
  • better blood circulation
  • proper digestion at night
  • mental wellbeing
  • better focus
  • more creative
  • less stress, depression, anxiety
  • better mood
  • better immunity

The Last word

The use of artificial light during the night should be controlled to allow children to sleep well. We should also take advantage of natural daylight and avoid homes and office spaces lit up by artificial light.

Here is what happens when we embrace natural light and darkness:

  • The more time we spend under natural visible light and darkness the less time we spend using electric light, specifically the blue and green light emitted by fluorescent tubes and bulbs.
  • By learning, living, playing, and working in places that take advantage of natural light, we become less susceptible to dangers caused by artificial light.
  • We also spend less money to maintain artificial lighting in our homes, offices, and schools.
  • We experience less eye-strain when we interact with natural lighting.

The natural synchronization of natural daytime light and natural night-time darkness can lead to natural synchronization of the 24-hour solar-day activities for humans, animals, and plants.