Alaska Sleep Education Center

How Does Light Affect Your Sleep?

Posted by Gabie Lazareff on Mar 2, 2021 9:53:42 AM

Young handsome blond guy looking at his phone

Have you ever dropped your phone on your face as you lay in bed at 1 am senselessly scrolling through Insta?.. You haven’t?! Oh… just me then I guess…  

It wasn’t just the dent in my nose or the thought of fixing my now broken glasses tomorrow that was keeping me up… although that didn’t help my restlessness either of course. 

What was making it impossible for me to fall asleep was the fact that I was on my phone, which emits blue light, which directly interferes with the natural production of the sleepy hormone, melatonin, making it very difficult to fall asleep.

Getting enough quality sleep is super important for our long-term health and wellbeing. If we think about sleep in terms of evolution and nature, we quickly understand just how vital sleep is to human survival. 

Is Sleep really that important?

Let’s think back to pre-civilisation. You’re a hunter/gatherer. You go out into the wilderness to source food to survive. You build a shelter for warmth. All around you are constant threats to your survival. Yet, nature requires you to be in the ultimate state of vulnerability for between 7-8 hours every. single. day. 

Obviously in modern-day society, most of us don’t have to be on the lookout for bear attacks. Back then, we were on a more frequent high alert. Sleeping, although necessary, was pretty risky at times! 

And yet, mother nature and evolution never got rid of it. Sleep has never adapted. We don’t have any tools while we sleep to protect us from outside dangers. 

So why do we still sleep? Why hasn’t evolution gotten rid of this incredibly vulnerable state of being that we need to be able to function properly? 

If evolution hasn’t gotten rid of sleep or found a way to reduce the amount of sleep we need, it must mean that in our current stage of human evolution, sleep is simply a necessity. 

If nature requires us to be in a vulnerable state for 7-8 hours every day, that is evidence that sleep must play a FUNDAMENTAL role in human survival.

What role does light play in our Sleep-Wake cycle?

Let’s keep imagining we’re hunters and gatherers. We’ve been out all day, sourcing food and staying out of harm’s way. We’re back at our shelter, and the sun is setting. It’s about 7 pm. By 8 pm, the sun has fully set, and we are asleep. 

The sun starts to rise at around 4 am. Before it’s fully risen, you’re already awake. 

You don’t have any tech, no alarms, you just naturally woke up at 4 am and naturally fell asleep at 8 pm.  

You fell asleep and woke up with the cycle of the sun rising and setting. Because this is how humans used to sleep - with the natural day-night cycle. 

Why do we get tired in the dark?

When the sun sets (and we aren’t using any other forms of light) our body naturally produces the sleepy hormone, melatonin, getting us into a sleepy state. 

Why do we wake up when it’s light?

When the sun rises (and we let the light in) the body naturally stops the production of melatonin, encouraging the body to awake. 

I’m going to guess it’s been a while since you fell asleep at 8 pm and woke up at 4 am. It makes sense that we don’t sleep like this anymore. We have electricity now! We can watch the sunset at 6 pm, turn the lights on and stay up until 1 am. This is because artificial light stops the production of melatonin just as natural sunlight does. 

Device Screens and Sleep

Devices with screens like smartphones, TVs, laptops, tablets and more contain a type of light called blue light. Blue light interferes with the brains’ natural production of the sleepy hormone, melatonin, essentially tricking the brain into thinking it’s daytime.

How can I leverage light to improve my sleep quality?

The term ‘midnight’ specifically refers to the middle of the night. This is because midnight used to be the middle of the night. Nowadays, it seems to be around the time that most of us start our sleep. The way that our society runs unfortunately doesn’t make it all that easy to follow our body’s natural sleep cycle, waking up and falling asleep with the sunrise and sunset. However, there are many ways that we can use light to encourage the body into a sleepy state before we go to bed and to help us wake up if it’s still dark. 

Turn the lights off!

Turning off the lights in your space 2ish hours before bed will really help to encourage the body into a sleepy state. If you enjoy watching TV before bed, maybe try watching TV in the dark and notice if this helps you feel tired earlier. 

If you’re a shift worker and need to sleep before it’s dark outside, try closing the curtains and/or shutters in your whole living space. You can also try wearing an eye mask before bed to encourage the production of melatonin. 

Turn the lights on!

If you’re a shift worker, you’ll know the struggle of trying to implement a regular sleep routine. Working hours frequently change, making it difficult to go to sleep and wake up at the same times. Sometimes, we might have to wake up while it’s still dark outside. 

If you’re struggling to wake up because it’s still dark outside, and your body hasn’t had the cue to stop producing and releasing melatonin, turn the lights on! Although natural light is better, any light will stop the production of the sleepy hormone melatonin, making it easier to wake up. 

You can find power timers available to purchase, which essentially turns whatever is plugged into it on and off with a set timer. Setting your lights to turn on when you’re supposed to wake up can be an effective alternative to an alarm. 

Put your phone away!

Try to avoid being on your phone for at least 1 hour before you need to go to sleep. Life happens though and sometimes this isn’t possible. If you think that you might not be able to do this all the time, buy yourself a glass screen protector that has a blue light filter. You can find blue light filters for all sorts of device screens. 


We underestimate just how important sleep is to our human survival and our ability to thrive. If you’re concerned that you might have a sleep disorder, be sure to speak with your healthcare providers about options for improving your sleep. Contact Alaska Sleep Clinic for a free 10 minute phone consulation.

Author Bio: Gabie Lazareff is a certified health coach, yoga teacher and freelance nutrition & wellness writer. She’s on a mission to spread the word about the importance of sleep in order for us not just to survive, but to thrive. 

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Topics: blue light screen, getting beter sleep

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