In this lesson, we will go into more depth to learn how both light and darkness affect our sleep.
Different types of light affect us differently when it comes to sleep. The light mentioned in this lesson is mostly centered on sunlight. I will touch on LED light briefly in this lesson, but will go into more detail about it in the next lesson.
Sunlight helps to keep our circadian rhythms in balance. What's a circadian rhythm? You may remember this from the very first lesson, but let's back up a bit.
Back in the pre-electricity days, the sun would go down, it would be dark, and people went to sleep. When the sun came up, it got bright, and they woke up. Circadian rhythms tell the body and brain that when it is dark outside, it's time to sleep, and when it is light out, it's time to wake up.
Exposure to the sunlight in the day keeps our circadian rhythms, sometimes called our biological clock, in equilibrium. Think of it as syncing your devices every time you come into contact with the Wi-Fi signal. Your body will sync with the daylight, and when it becomes night time, your body starts preparing itself for rest. If you can spend the whole day outside, that'd be great! However, it is often unrealistic for most people.
But if you can get natural light exposure at least 30 minutes a day, this can help your sleep. Even better would be exposed at least once in the morning, middle of the day, and towards the end of the day.
Natural light exposure helps maintain a healthy sleep/wake cycle. While it is important to get sun exposure in the day, it is equally important to control your exposure to light when you sleep.
Have you ever fallen asleep with the lights on? I'm betting you didn't sleep the night. More likely, you woke up partway through the night, even if only to shut the lights off.
Bright lights can interrupt the body's natural sleep pattern. Some people can't fall asleep if there's too much light. Again this goes back to our pre-electricity days where when it was dark, it was time to sleep. Certainly, the darker you can make your room, the less likely light will wake you up.
Shift workers can have a very hard time trying to sleep after work. While the rest of the world is awake and enjoying the sunlight, they need to shut it out; otherwise, it doesn't allow them to sleep as well. Did you know that even if your whole body is covered, but your foot is hanging out of the blankets, and the sunlight is hitting it, this will start the waking up process? This is because your skin has receptors that detect sunlight.
If you have an alarm clock with bright numbers, turn it on its face or against the wall. The light could affect your sleep. Also, if you wake up in the night and see the time, you may develop anxiety about what time it is versus when you need to be up. This anxiety will make it difficult to get back to sleep. If you wake up and don't know what time it is, but see it is still dark, you will more likely be able to fall back asleep and quickly.
Moonlight, too, can wake you up by slowing melatonin production. After all, moonlight is just reflected sunlight. Use blackout curtains if needed. If you are prone to waking up at night to use the bathroom, use night lights. Leaving a hallway or bathroom light on maybe too bright and not allow you to fall back asleep as quickly after returning to your bed.
Remember: control your exposure to light. Darkness is a cue for your body to sleep. Another source of light is unnatural light, such as TV screens, tablets, phones, computers, etc.
In the next lesson, entitled “The Negative Effect of LED Light on Sleep,” we will be going into more depth about LED and blue light exposure. Until then, happy Zzz's.