Opening and closing our eyes are definitely related to sleep & wake changes, did you ever wonder why?
Melatonin, the hormone of sleep, is being synthesized in the pineal gland, a tiny structure in the human brain located just behind the upper part of the brainstem.
Just by its location, a lot can be learned about its importance. Being in charge of melatonin production and secretion, the pineal gland plays a huge role in overall health and well-being, participating in many important physiological pathways. Nonetheless, melatonin is also produced, in much smaller quantities, within the eye. Wait, what?
The melatonin cycle is directly dependent on light stimulation. Light influences the cells in charge of melatonin production and secretion, thereby the connection between one’s sight and their ability to fall asleep and stay asleep.
“In modern societies, artificial lighting greatly affects biological rhythms. People are increasingly exposed to excess levels of arti-ficial light during the night-time, leading to chronodisruption, and resulting in impaired physiological, behavioral and biochemical rhythms”
Our circadian rhythms are dependent on the light and dark regular patterns, mediated by melatonin. It seems like in modern times the use of artificial light during night time has a significant impact on this complex system of circadian rhythms. Therefore sleep problems such as insomnia can actually be treated by light therapy, light exposure during different times of the day and night, in order to achieve the natural circadian rhythm again.
Moreover, different eye conditions can also affect light transmission and therefore influence melatonin production and secretion, and as a result, damage the quality of sleep. It was actually shown that cataract surgery increases salivary melatonin levels and improves sleep.
While the idea of the effect of light over sleep is no news, the opportunity to treat sleep-deprived related medical issues with light exposure and melatonin regulation is pretty mind blowing. The option to improve symptoms of insomnia and its outcomes can exponentially improve people’s health and well-being, and so it is for many other sleep-related issues.
Wishing you bright days, light-free nights, and a good night’s sleep