What do you associate most with sleep? For us it’s getting into pyjamas, turning off the lights and curling up in bed. We got to bed at night, therefore we mostly associate sleep with darkness.
Turning the lights off while we sleep isn't just something that we're conditioned to do, there are also biological and physiological reasons for it.
Everybody has a preference. If you enjoy sleeping with the lights on or you're afraid of the dark, then that’s totally fine, but understand that it might be affecting the quality of your sleep.
In this article, we discuss why it’s the standard to sleep with the lights off and how light can affect our sleep-wake cycle.
Let's talk about circadian rhythm first
You might be familiar with the phrase "circadian rhythm"; it's basically our internal body clock. Our circadian rhythm dictates when it's time for our body to be awake, and when it is time to rest and sleep.
If you've ever wondered why we're all accustomed to being awake during the daytime and asleep at night time - it’s based on biology rather than choice.
Our wakefulness during the day is an effect of light exposure to our body. Our brain may decide to wake us up when bright light is present.
At night when we are less exposed to light, our brain's pineal gland secretes an enzyme called melatonin, that helps put us to sleep.
How does light affect your ability to sleep?
The pineal gland only secretes melatonin when there is a reduced exposure to light sources - whether natural or artificial.
The way it works is that when your eyes see bright light, such as in the outdoors, or your phones, TV screens, and bedroom lights, it sends a signal to your brain that it is still daytime, regardless of the actual time.
When our brain thinks that it's daytime, it intentionally suppresses melatonin production which our body requires for us to fall asleep.
Sleeping with the lights on isn't impossible and it isn't uncommon, but it's just physiologically easier when they're off.
So, is it normal to sleep with the lights on?
There's nothing wrong about sleeping with the lights on and some people prefer it that way, but there are more benefits to sleeping with the lights off.
The benefits of sleeping with the lights off
You have better sleep quality
If you compare the sleep quality of people who sleep with lights on and people who don't, those who sleep with the lights off spend more time in a deep sleep.
You can easily enter deep sleep when more melatonin is produced, which allows your body to rest and repair better during your slumber.
You're less likely to develop sleep disorders
Sleep deprivation and chronic insomnia are more likely to occur in people who are exposed to bright light before and during bedtime.
Due to the lack of melatonin production, the body only relies on fatigue and the lack of energy to fall asleep - and if you're not that tired, you could be up all night.
Dimming the lights or turning them off completely before you sleep helps your brain learn that it is time for bed.This can help condition your body to know when to fall asleep and it helps produce more melatonin that you need for a good night's sleep.
It regulates your blood pressure
Melatonin doesn't only help put you to sleep, it also helps regulate your blood pressure, both during the day and when you’re asleep at night.
It’s normal for blood pressure to drop during sleep, which helps with the body’s restorative process.
Exposing ourselves to light and therefore stopping the melatonin production at night can cause a rise in blood pressure.
What can you do if you can't sleep in the dark?
Use a night light
Night lights operate differently than regular room lights and are a great option if you’re not willing to completely switch off the lights.
Pick a night light that emits a warm tone, as the wavelengths of the warm coloured lights do not affect melatonin production as much as cooler tones.
Also, be mindful of the amount of brightness that your night light emits. Pick a night light that just has enough illumination for you to see what you need and not bright enough to lighten the entire room.
Using a night light is also great for children who are scared of the dark. It's a great option for kids who need a little bit of dim lighting but it won’t completely disrupt their sleep.
Reduce light exposure little by little
If your bedroom lights have a dimmer, you can use that to train yourself to fall asleep in a darker environment.
You can begin by adjusting the amount of light in your bedroom and reduce it as the days go by, until you can comfortably fall asleep in the dark.
Develop healthy sleep habits
Before going to sleep, you can try implementing a nighttime routine that can help tell your body it’s time to wind down for bed, helping you sleep better.
Some sleep habits include showering before bed to lower body temperature, keeping the bedroom quiet, meditation or yoga, and turning on air conditioning to keep yourself cool during bedtime.
You can also reduce the use of gadgets and other electronic devices before you sleep, as the screens emit a lot of blue light which can easily cancel out melatonin production.
But if you're struggling to switch off from your devices, you can use your phone's night mode. This shifts the screen colour to warmer tones, and with a low brightness setting it shouldn’t impact your sleep too much.
Reducing the amount of artificial light that we see from screens can allow our body to have adequate melatonin levels, giving us better sleep quality.