Light does more than just help us see, it is also an important means of regulating our biological rhythms and affects our general well-being. Light influences whether or not we are awake, focused and productive and feel energized and healthy.
Scientific studies have confirmed the biological effect of light on our body. Ultraviolet light, for example, influences the production of vitamins. Exposure to bright light and, in particular, the portion of blue light affects our hormonal balance. Hormones in the body regulate how a person feels as well as their sleep-wake cycle. In daylight, the portion of blue light is relatively high, whereas it is significantly reduced in the evening.
When it's bright outside, the body releases serotonin – also known as one of the "happy hormones" – and cortisol, a stress hormone. Both of these make us feel awake and active. However, melatonin is considered a sleep hormone and causes us to feel tired and sleep soundly when it is dark.
Light, in particular blue light that reaches the retina, also affects our psychological well-being. That is why light therapy is successfully employed to treat winter depression and insomnia. But, as is so often the case, the axiom "everything in moderation" still applies. Exposure to too much light also carries certain risks and can even be damaging.