COGNITIVE WINDOW 2: Why are light and darkness important for rest and regeneration?
Light plays a key role in our lives, affecting our moods, alertness and the quality of our sleep. It may surprise you, but it is the light during the day, the loss of light in the evening and the absence of light at night, that has a major impact on how well we sleep.
Why are light and dark important for sleep?
- Melatonin: Darkness stimulates the production of melatonin, the sleep hormone. Melatonin calms us down, lowers body temperature and prepares the body for sleep and night-time recovery. Its level is significantly influenced by the sufficiency of the hormone serotonin.
- Circadian rhythms and serotonin: Light and darkness help us to maintain our internal cycle of about 24 hours â the circadian rhythm. This rhythm regulates our bodily functions, including sleep and wakefulness. The production of the night-time hormone melatonin is conditional upon us indulging in plenty of quality light during the day and the resulting production of the hormone serotonin.
- Darkness and relaxation: Darkness eliminates visual sensations, which calms the brain and creates an environment for relaxation and unwinding.
What light and when does it harm us, and when does it help us?
- Blue is not good. In particular, blue light emitted from electronic devices (mobile phones, computers, tablets, TV monitors) before bedtime suppresses melatonin production and disrupts our sleep cycle. In general, exposure to any light containing blue, cyan and green spectral components in the hours before bedtime can make it more difficult to fall asleep and reduce the quality of the bodyâs repair processes during sleep.
- On the other hand, the cyan component during the day (preferably from natural sunlight or light that is as close to sunlight as possible) creates the conditions for a good nightâs sleep. Cyan stimulates the production of serotonin, from which melatonin is formed during sleep, which, in turn, creates serotonin once again… If this cyclical process is disturbed in the long term, a so-called social jet-leg is created, which can cause a number of diseases of civilization.
How to improve sleep quality with light?
- Dark bedrooms: Invest in high-quality blackout curtains or eye masks.
- Avoid the blue, cyan and green light in the evening and at night: Avoid using electronic devices at least 90 min before bedtime. If this is not possible, use night light filters or safety glasses.
- Daylight: Expose yourself to the most natural light. This will help synchronise your internal clock and improve the quality of your nightâs sleep.
- Choosing the best artificial lighting. If you have to spend more time indoors, use the best quality artificial lighting that is close to sunlight in spectrum.
How circadian biodynamic artificial lighting helps
A smart control system in the interior ensures illumination with LED light simulating the natural alternation of light and dark. The daily routine soundly stimulates the bodyâs activity like the sun on a clear day; the evening, warm white light induces relaxation like the setting sun. Night lighting reminiscent of an orange-coloured fire provides illumination for basic orientation, but does not wake the body into a mode of activity.
