How Light Affects Sleep

We all know that darkness is essential for a good night’s sleep. Few, if any people sleep with the lights on and most of us shudder at the thought. As obvious as it is that we need darkness to sleep, it’s easy to overlook the other ways in which light affects our sleeping habits. To put it simply: darkness makes us tired and light tends to keep us awake. But in recent years, scientists have discovered that it’s a little more complicated than that. Here’s everything you need to know about how light and the lack of it affect your sleeping habits.


Circadian Rhythms

Our bodies do a pretty good job of functioning on their own. There are a lot of things that our bodies do “automatically,” such as breathing, digesting, and beating your heart. Another one of those functions that our bodies do a good job of doing on their own is sleeping.

Everybody has what’s called a circadian rhythm, which is our bodies’ internal clock that tells us when we should go to bed and when we should wake up. Humans are not nocturnal creatures, so our bodies default to waking up during the day and sleeping during the night. And what signals to our bodies whether it is daytime or nighttime? You guessed it: The amount of light.

Darkness Promotes Sleep

As it gets darker each evening, our bodies produce melatonin, a hormone that tells the brain it’s time to sleep. Melatonin levels naturally rise as the evening progresses, sending signals to our bodies to wind down and relax. It’s important to note that it is the darkness (among other things) that tells our bodies to produce melatonin and start preparing to sleep.

Light Hinders Sleep

Here’s where we run into problems: just as darkness invokes sleep, light does a good job of preventing it. Before the invention of artificial lights, phones, TVs, and other electronics, there wasn’t much of an issue with lights interfering with sleep. But these days, the lights emitted from such devices tell our bodies that it’s still daytime and prevent us from producing the melatonin we need to sleep. Several studies have been done, supporting the idea that the use of technology before bedtime has a negative effect on sleep.

What Now?

Now that you know how light affects your sleep, it’s up to you to take charge of your sleeping habits and use this trick to your advantage. If you’re prone to sleeping in every morning, turn the lights on as soon as you wake up. If you have trouble falling asleep at night, put down your smartphone and dim your lights an hour or two before bed. Taking small steps like these will have a huge impact on your sleeping habits!