Today the crisp, bright glow of LEDs surrounds and lights our world day and night. You stare at brightly lit computer screens and phones all day. You might wake up and go to sleep illuminated by the glare of an alarm clock. Your phone and bedside tablet flash notifications in the night, and you watch TV when you are relaxing before bed. Then there are the countless little lights on all our electronics that glow and blink.
All of these artificial lights are bad for our sleep patterns, and the light from LED screens are often the worst. They emit high amounts of short wavelength (blue) light, which has the strongest effect on melatonin — our sleep regulating hormone. They emit far more of this light than any natural source. What this does is change our sleep pattern and our entire circadian rhythm — we are delaying our body’s entire schedule for falling asleep. We’re more likely to lay awake in bed and stay up later than we want. It means many of us get less sleep than we need and some might be going through life in a tired haze that never lifts.
The large amount of artificial light shining at us at night is a recent development. In the middle of the 20th century the only light you might have seen while trying to sleep came from exterior lights shining in through windows if you lived in an urban area, and that could be blocked by curtains. No one peered at computer screens and few, if any depending on the decade, watched television just before bed. Go back earlier and you realize that for virtually all of human history we slept during much darker nights. No one saw little bright artificial lights scattered through their home tricking their brain into staying awake.
The first thing to understand is that it isn’t all light that will make it difficult for you to sleep. Total darkness is best, but some kinds of light before going to sleep are better than others. Think of it this way: light at the blue end of the spectrum is the worst and will keep you awake. Light at the red end of the spectrum won’t.
Sunlight and the daytime sky is blue, while something like a fire from a hearth in the evening is more red. Modern LED bulbs and what you see on a computer screen will almost always radiate lots of blue and white. The kind of artificial light people in the middle of the 20th century would have seen before bed came from old-fashioned incandescent bulbs that tend to have more orange wavelengths.
What You Can Do
How long before bed should you stop exposing yourself to short-wavelength light? About one to two hours. It may not be easy for a lot of people. We are surrounded by screens and LEDs, and we are creatures of habit. Below are some steps you can take or at least consider.
Step 1: Make sure you won’t see any light from your phone.
This is an obvious step. You can turn your phone off, you can hide it in a box, you can put it in a mode where it won’t light up with notifications. It’s fine if you still need to hear it for emergencies or work, but you don’t need to see the notification lights.
Remember to cover up any other little electronic LED lights in your bedroom. If there’s something you can’t turn off then consider hiding it or even using electrical tape to cover the light.
Step 2: Get an old-fashioned alarm clock.
You don’t need to have an alarm clock beaming into your face all night. I personally like the classic twin-bells style alarm clock. Most twin-bells alarm clocks you find for sale today run on batteries and don’t need to be wound. Some come with back lights you can switch on or off, some are designed to be silent tickers, some have luminous dials you might want to avoid, but they all share that same classic design and won’t destroy the healthy dark of a good night’s rest.
Step 3: Get a lamp and use an orange bulb.
Don’t use your regular overhead daytime lights. In most homes those are designed to flood a room with light and make it feel like day. The warm, comforting glow of a lamp at night will give you all the light you need and keep your brain focused on the fact that it’s night-time. You can use old-fashioned incandescent bulbs with a lamp shade to keep the light dim and orange, but there are LED options as well if you want modern energy efficiency. Think of a lamp as the modern echo of the comforting light of the hearth.
Step 4: Read real books or listen to radio plays before bed.
Avoid watching TV or playing video games. Reading is great, but beware of eBooks. eReaders and tablets are usually just big bright screens and won’t help you get to sleep as well as a real book. A 2014 study found that we take longer to fall asleep after using an eReader than a physical book. Some eReaders/eReading software have a night-time mode where the screen dims to a dull orange, but it’s still not as good for sleeping as a real book.
You could also listen to radio plays. Listening to a story at night before bed by the warm glow of a lamp that radiates similar orange light to a fire hearkens back to deep, primal times in our history. It is something like the ancient bard reciting a tale by the campfire, but in the comfort of the modern home and civilization.
I personally found all of these have helped me sleep better. I notice how much longer it takes me to fall asleep when I go to bed after staring at my computer screen. When I’ve given myself time away from that light before bed I feel more relaxed and as if I’m living the way we evolved to live.
It might take some getting used to when you wake up in the middle of the night and find your bedroom darker than you’re used to, or to read a physical book or listen to a story before bed instead of watching Netflix or browsing Reddit, but it’s a healthy switch to make that works better with the way our brains and bodies evolved.