Humans are diurnal, meaning we are normally programmed to sleep during the night and are active during the day (unlike our koala friends). Our circadian rhythm is regulated through our optic nerves. Our bodies are signalled to stay awake when light enters our eyes and triggers communication via our optic nerves. When light wanes and we enter darkness, our brains are prompted to produce and release the sleep-inducing hormone, melatonin.
Without darkness, our body doesn’t know when to produce/release melatonin.
So what happens when you're exposed to constant light?
The summer solstice in Australia is fast approaching. However, unlike our clients and friends in the northern hemisphere, we don't get to experience perpetual daylight during summer! In places like Scandinavia, their summer break allows for fun and excitement after long, cold and dark winters. But being exposed to light when one should normally be experiencing a nocturnal period, can lead to sleep deprivation and other sleep-related health issues.
This seems to be more of an issue for us as visitors than it is for the locals. We can definitely vouch that the lack of darkness completely threw our sense of time out the window. If it wasn’t for block-out curtains, eye masks and melatonin there is no doubt a zombie transformation would have occurred!
For those in the southern hemisphere, enjoy your summer downtime! And for our friends in the north, your time in the sun will come (in precisely 6 months!).
For more information on light and circadian rhythms, read our previous blog posts here: