How Does Light Affect Your Sleep Habits?

How does light affect how we sleep? It is one of the most important factors that affect how well we sleep. It regulates our circadian rhythm, which is the rhythm throughout the day where sometimes we feel like we have more energy, sometimes there might be a lull, sometimes we might get tired, sometimes we might be very alert (when we wake up ideally).

Light & Your Circadian Rhythm

Light helps determine the melatonin that we create and release. And the new issue is that light is very different than it was in the old days.

And by this, I mean that there's a lot of cheap electricity and powerful lights. If you put those things together, there's a certain issue that develops from that because, in the old days, light was very expensive. You think of candles and we just didn't have as much light. Now we have it everywhere.

So natural light is very important for developing and regulating our circadian rhythm. We see it in the morning at sunrise and it looks different than it does in the evening at sunset. It's very bright at noon if there are no clouds.

Blue Light

Also, we have to think about the different wavelengths of light. Blue light is very short and powerful. In the natural world, we only see these wavelengths around noon. In the morning it might be bright but there's very little blue light, in the evening it might be bright, but there's very little blue light.

Now, however, we think about all the smartphones we have with the LED screens, all the TV monitors that are flat screen, all the computer monitors, and they put out a lot of light in the blue light spectrum.

Exposure to blue light can cause some problems with sleep and it can worsen metabolism, prevent weight loss, cause some cardiovascular problems, and even elevated cancer risks can result from this.

A quick background about melatonin. Melatonin is a hormone that is produced when our eyes see light and drowsiness increases with higher melatonin levels. In the evening, ideally, there's less light, especially blue light, so there's more melatonin and we feel drowsy. However, as I just discussed this doesn't really happen these days with all the computer screens and whatnot. 

One strategy to help you sleep better is to reduce blue light exposure in the evening. There are a couple of ways to do this. A lot of computers and TVs and smartphones have settings that are called nightlight or night shifts or some such, and it changes the blue light wavelengths that would go through and make them a little bit warmer, orange or red.

There also some blue light blocking glasses, which are usually yellow lenses or orange lenses that cut out a lot of the blue light. And also if you can just reduce the use of screens in the evening, but of course that is not the easiest to do.

Manage Light While Sleeping

While you're sleeping, to manage your light, there are some things you can do. One is blackout curtains. These are beneficial to prevent a lot of light from entering your bedroom, especially now that LED street lamps are becoming popular because, again, they're so cheap. When it comes to electricity usage blackout curtains can be very beneficial.

The other one is nightlights. If you need nightlights, please think about using orange or red night lights. They don't put out blue light wavelengths at all for the most part. And if you do go to sleep with the TV on, be sure to think about using a sleep timer that will turn the TV off, maybe 15 minutes after you're asleep if you can manage that.

And I wish that eyelids were enough, but light does sip in through the eyelids. So that's why curtains, glasses, and sleep timers on your TV might be very beneficial also because the light comes in through the eyelids. If there is light exposure at night, it can cause eye strain, weight gain, and breast and prostate cancers have been associated with this.