It is now well-known: light is one of the essential elements in our sleep-wake
Indeed, the type of light present in the environment is connected to producing
different kinds of chemical compounds.
To understand this, we can take a look at the diurnal variation of light. While
there is more bluish light, we are more inclined to produce excitatory hormones
(first and foremost cortisol). On the other hand, during the late afternoon,
when the light is reddish - hormones are linked to more relaxing effects (i.e.,
melatonin). Notably, the production of hormones affects our sleep-wake cycle and
interacts with our mood, emotions, and feelings. In other words, the type of
light surrounding us, and therefore the type and quantity of hormones produced,
influence our mental life.
The reasons listed above make it clear why many sleep experts recommend
meticulous care in setting home lightings, particularly in the bedroom.