Our sleep- and wake- cycles are inextricably linked to light.
We humans evolved to adjust to the predictable light and dark phases of the sun to set our internal, circadian clocks.
When it’s light out, the day starts and we need to wake up. Our body starts processes to energize us and wake us up. When it’s dark, the night starts and it’s time for us to fall asleep. Our body produces hormones that make us tired and help us fall asleep.
It used to be that simple.
But over the last few hundred years when artificial light invaded our lives, it got complicated.
Our days got longer. And our nights got shorter.
From street lights to lightbulbs, televisions, computers and smartphones - nowadays, we can be exposed to light all-day long.
Instead of a natural 12-hour days, we can now artificially create 24-hour days with nonstop light exposure.
This constant light disrupts our natural light and dark cycles. Studies show that exposure to room light or bright screens during usual hours of sleep suppresses melatonin levels (the sleep-regulating hormone that makes you feel tired) by more than 50% And both the quality and the quantity of our sleep suffer as a result. We become tired later and find it harder to fall asleep if we want to.
Our underlying biology is the same as it was millennia ago: we require darkness to become tired naturally. And our genes expect us to sleep in total darkness.
The first rule of quality sleep is: embrace the darkness at night and light during the day. Get more sunlight exposure during the day, and less light exposure at night, and you’re on your way to better, deeper sleep.
NO ELECTRONICS BEFORE BED OR IN YOUR BEDROOM
At least 50% of Americans sleep with their cell phones right by their side. Many of them admit to checking notifications and messages in the middle of the night.
Unfortunately, the blue light coming from your phone or laptop screen is the WORST type of light for your sleep. It triggers your brain to secrete more daytime hormones and suppress your nighttime release of melatonin - which will disrupt your normal sleep cycle and can give you major sleep problems.
We are just not designed to stare into the type of light emanating from these devices.
Our brains perceive this as if we’re staring at the sun, and keeps us up accordingly.
Plus, the dopamine rush you get from browsing makes you alert and awake.
Cutting out some screen time at night is likely the number one thing you can do to improve your sleep immediately.
TO SLEEP BETTER:
1. Keep your electronics out of your bedroom (phone, computer and TV). You don’t need these by your side at night.
2. Use a real alarm clock to wake you up instead of your phone. This way, you avoid the temptation to check your phone at night.
3. Turn off all screens at least 90 minutes before bedtime to allow your body to normalize your cortisol and melatonin levels). Instead, read a book or do something relaxing or social.
4. Turn off the notifications on your devices at night (or put them in Airplane mode) to avoid being woken up.
5. Block the blue light on your phone and computer at night. Set up the (free) applications f.lux on your computer, Night Shift on your iPhone or Twilight on your Android phone.
BLACKOUT YOUR BEDROOM
ANY source of light in your bedroom will make it harder for you to fall asleep.
If there’s any light in your bedroom, your body will pick up on it, and send messages to your brain that can disrupt your sleep patterns.
So, do what you can to darken your bedroom and make it pitch black. Even during daytime, your bedroom should be so dark that you can’t see your hands in front of your face.
TO SLEEP BETTER:
1. Get blackout curtains in your bedroom to block out any light from outside.
2. Move any sources of light out your bedroom.
3. Put the display of your alarm clock out of sight.
4. Block any remaining light that sneaks into your bedroom with blankets or tape.
5. Use soft light or candles in the evening, instead of bright light to transition into the darkness.
GET DIRECT SUNLIGHT
Your body expects you to get a lot of sunlight in the day. It NEEDS the sunlight to sync your circadian timing system, and also your SLEEP cycle.
Light tells your brain, organs and glands to be alert and “wake up”.
Light exposure (and especially sunlight exposure) triggers your body to produce optimal levels of daytime hormones, and neurotransmitters that regulate your biological clock.
Too little light exposure during the day, and too much artificial light exposure in the evening throws your circadian rhythm out of whack.
Don’t get enough bright light during the day (or too much at night) will make it harder for you to become tired, fall asleep and stay asleep.
When it comes to light, there’s no substitute for direct sunlight. Even a cloudy day is 10x as bright as regular indoor lighting.
TO SLEEP BETTER:
1. Get some sunlight as soon as possible when you wake up to sync your circadian rhythm. Open the curtains, or go for a walk outside early in the morning.
2. Try and get at least 30 minutes of direct sunlight each day by being outdoors.
3. If you’re stuck inside all day long, spend your breaks outside or near a window to catch some sunlight.
4. If there’s hardly any sunlight outside, consider getting a “light box” that mimics sunlight.