A luminous truth: Why you need more sun – and less screen time
We protect our skin from the sun – but who actually protects us from artificial light?
In a time when screens and LED lamps dominate our daily lives, we often forget that sunlight is our most powerful source of life. It nourishes body, mind, and soul – and is far more than just brightness.
Can you feel the difference when sunbeams touch your face?
Natural light activates processes within us that no artificial light source can create. It regulates our internal rhythm, supports the synthesis of vitamin D, strengthens the immune system, and improves our mood.
But that's just the beginning. Sunlight penetrates to the deepest layers of our biological system:
It harmonizes hormones, improves sleep, increases energy and contributes to bone health.
Even our concentration and productivity depend on how much natural light we absorb daily.
"El ser humano antiguo sobrevivía. El ser humano moderno subsiste."- Carlos Stro, light researcher from his book: Supervivir - Vuelve al origen y recupera tu salud
In other words: "The ancient human survived. Modern human merely exists."
These words remind us that we have lost our original connection to nature – and with it, the understanding that sunlight is part of our biological design.
Barau sees the conscious return to natural light as a form of self-care: a return to life itself, to energy, clarity and genuine regeneration.
Humans are biological beings that react to environmental stimuli – and one of the most important of these is sunlight, because without it our body loses its orientation: hormonal axes become unbalanced, inflammation develops gradually, and the nervous system remains in a state of constant activation, the so-called sympathetic nervous system.
The morning sun sends the signal "It's daytime" to the retina. This information synchronizes thousands of internal clocks – in the skin, liver, heart, intestines, and muscles. This tells the body when to burn energy, eat, think, or rest.
In the evening, however, the warm light of the sunset signals: "It is time for regeneration."
“La salud empieza en la luz y con la luz.” – Carlos Stro, Supervivir Podcast, Part 1
In other words: "Health begins in the light – and with the light."
That's why the first and last minutes of daylight are true medicine.
They promote the release of serotonin and melatonin, strengthen the immune system and help to stabilize the internal clock – gently and without any side effects.
Melatonin – the hormone of night and balance
Melatonin is the hormone that signals to our body that it's time to rest. It is produced in the pineal gland as soon as it gets dark – controlled by the light signals that travel from the eyes to the brain.
However, to produce sufficient melatonin at night, the body needs real sunlight in the morning and during the day. Bright daylight calibrates our internal rhythm and ensures that melatonin synthesis begins on time in the evening.
However, if we spend most of our time under artificial light – especially in front of screens with a high blue light content – this natural cycle is interrupted.
Blue light tricks the brain into thinking it's daytime, even when it's actually night. As a result, melatonin production is blocked, sleep patterns are disrupted, and nighttime regeneration is prevented.
In the long term, this constant stimulation leads to a state of perpetual alertness: the body can no longer distinguish between activity and rest. Concentration problems, irritability, weakened immune system, and hormonal imbalances are often silent consequences of a disrupted light-dark cycle.
Melatonin is therefore much more than a sleep hormone – it is a signal of balance between light and darkness, activity and rest, the outside world and inner life.
Those who regularly expose themselves to natural light protect this balance – and thus strengthen their entire system.
Each color of light has its own effect.
- UV light (≈ 280–400 nm) penetrates deep into the skin, stimulating the production of vitamin D, melatonin and dopamine.
- Infrared and red light (≈ 700–1400 nm) penetrate deep into the cells, stimulating blood circulation and regeneration, and having a calming effect on the nervous system.
- Darkness (absence of light) activates melatonin production in the pineal gland and enables the glymphatic system to detoxify the brain. Without true darkness, nighttime regeneration remains incomplete.
See the illustration below:
The sun changes this spectrum throughout the day.
In the morning and evening, gentle, long wavelengths (red and infrared light) dominate, while at midday the shorter, activating blue wavelengths prevail. This natural sequence is the foundation of our inner balance.
"Light is not just brightness – light is essential." – Dr. Alexander Wunsch, physician and photobiologist
See the illustration (source: https://www.lichtmikroskop.net/optik/lichtspektrum.php)
Natural light has a different power.
What many don't know: The difference between indoor and outdoor light is enormous – not only in its effect, but measurable in lux, i.e., illuminance.
Indoors – whether at home or in the office – the values usually range between 100 and 500 lux. Even well-lit workplaces rarely reach more than 1,000 lux.
Outdoors, however, the dimensions are completely different. On a sunny day, natural daylight easily reaches 50,000 to over 100,000 lux.
Even under cloudy skies, there are still 10,000 to 20,000 lux – up to a hundred times more than indoors.
This enormous light intensity is one of the reasons why a walk outdoors is so invigorating. Our eyes and skin perceive not only brightness, but also the biological signals of sunlight – impulses that regulate hormones, mood, and energy levels.
In contrast, artificial light
The blue light emitted by screens, in particular, acts like a constant disruptive impulse.
It tricks the body into thinking it's experiencing daylight, even when it's already night.
The result:
Sleep problems, hormonal imbalances, exhaustion, and a silent decoupling from our natural biology.
Therefore:
We need not more light, but more natural light.
A breakfast on the balcony, a walk in the midday sun or a few minutes barefoot in the garden are enough to calm the nervous system and gather new energy.
See the illustration (source: https://www.lichtmikroskop.net/optik/lichtspektrum.php)
These simple steps will help you maintain your balance:
- Greet the day outdoors within the first 30 minutes of waking up – even if it's cloudy.
- Let your eyes absorb natural light repeatedly, without glasses or windows in between.
- Open the windows in the office regularly, stay in bright rooms, and take breaks from the light.
- Whenever possible, watch the sunset – it acts like a biological switch for rest and sleep.
- Practice grounding. You can find our blog post about it here . Ground yourself by walking barefoot on sand, grass, or soil. This enhances the regenerative effect.
Our well-being depends heavily on how well our body can distinguish between light and darkness. A disrupted light-dark cycle can cause many physical and emotional problems in the long run. Learn more about this – and how you can consciously stabilize your circadian rhythm – in the next article in our Wellness Techniques series. 🌙
👉 Make sunlight a regular part of your everyday life again –
Not as an obligation, but as an invitation to connect with life itself. Sunlight is nature's preventative medicine – free, beneficial, and always available. 🌞
Source:
📘 " El ser humano antiguo sobrevivía. El ser humano moderno subsiste. " - Carlos Stro, light researcher from his book: Supervivir - Vuelve al origen y recupera tu salud
📘 “ La salud empieza en la luz y con la luz.” - Carlos Stro, Spotify Podcast Part 1
📘 “Light is not just brightness – light is essential.” – Dr. Alexander Wunsch, physician and photobiologist
