Sunlight

First of all, daylight is our natural clock, without which our days would be unstructured, our sense of time would be disturbed and our biorhythm would be out of balance [1]. This is because daylight, with its particularly high blue content, is absorbed by the sensory cells in our eyes and suppresses the production of the sleep hormone melatonin [2]. This keeps us awake during the day and makes us tired in the evening due to its absence. 

Daylight also puts us in a good mood: it boosts the body's own serotonin production; a lack of light often affects our mood - who hasn't experienced the winter blues [3]! 

If that's not enough of an argument for you, perhaps the following will convince you to go outside regularly, especially in the dark season and during lockdown. After all, daylight is the only way to stimulate the production of vital vitamin D and ultimately strengthen our immune system. This in turn prevents osteoporosis and flu-like infections[4]. 

And even if the eye hardly notices a difference, it receives many times more light outdoors than indoors [5]. 

So put on your autumn coat and get out into the colorful leaves and sunshine! 

Quellen:

[1] Willard, L., (2006): Introducing biological rhythms. Springer Verlag.

[2] Hraska, J., (2015): Chronobiological aspects of green buildings daylighting. Renewable Energy: An International Journal.

[3] Beute, F., Kort, Y.A.W., Salutogenic Effects of the Environment: Review of Health Protective Effects of Nature and Daylight, (2014), Applied Psychology: Health and Well-Being, 6(1), S. 67-95

[4] Lim, S.M., Park, Y.H., Yang, K.I., Kwon, H.-J., (2010): Effects of daylight saving time on health. Journal of the Korean Medical Association, 53(2), S.155-S.163.

[5] Aries, M. B. C., Aarts M.P.J., & van Hoof, J., (2013): Daylight and health: A review of the evidence and consequences for the built environment. Lighting Research and Technology.