How Light Affects Sleep

It is important to get enough sleep every night so that we can stay healthy and function properly during the day. Everyone should be able to wake up in the morning feeling well rested and ready for the new day.

Too many people don’t, and there are a variety of reasons. I’m going to talk about one that many people probably don’t know much about. How light affects sleep.

Melatonin Regulates Your Sleep/Wake Cycle

The normal sleep cycle for humans is to be awake during the daylight hours and asleep during the nighttime hours. Your body’s sleep/wake cycle is regulated by a hormone called melatonin which your body produces when it is dark. When your body is producing melatonin you feel sleepy and fall asleep. When your eyes receive bright light, like daylight, melatonin production is suppressed and you wake up.

Our sleep cycle gets messed up when we mess with how our body receives light. During the day we shelter ourselves against the sunlight, not always intentionally. During the day most adults are at work, stuck inside under artificial light that is usually dimmer than sunlight. If we even get the chance to get outside while the sun is up we make sure we have our sunglasses on, so the light stays dim to our eyes. Melatonin isn’t adequately suppressed and we don’t fully wake up.

In the evening when the sun is going down we turn on lights in our homes, watch the brightly lit TV , and read on brightly backlit computer and tablet screens. This is probably the brightest light exposure we have experienced all day, so melatonin production is further suppressed when it should be building to help us fall asleep.

During the night, the bedroom is probably darker, but it is probably still lit up some from the digital alarm clock and the standby LEDs on all of the electronics. A lot of people also have night lights that, while dim, light up the room at night. You may also have outside lights, streetlights or other security lights, that shine in through your bedroom window too. Again, melatonin is somewhat suppressed by this light and we don’t sleep as deep or long as we should.

Some Solutions

We need to make sure that we get enough light to fully wake up during the day and reduce the amount of light we are exposed to in the evening and at night so that we can fully sleep.

Daytime Solutions

During the day we need to get enough light, especially in the morning, to suppress the melatonin production and fully wake up. If the sun is up before you go to work, try driving to work without your sunglasses (unless the sun is directly in your eyes, of course. Be safe). You could also take a short walk before you start work or during a morning break.

While at work, or whatever you do during the day if you are stuck inside, try to sit near a window to get exposure to the brighter light. If you can’t do that, then get a full-spectrum desk lamp. Full-spectrum light more closely approximates the frequencies that are found in natural sunlight and will give you some of the benefits of sunlight when you cannot get outside.

I use the Nikken KenkoLight full-spectrum desk lamp when I need to be able to see inside and cannot be near a window. It uses LEDs so it doesn’t require as much power as other lamps and it has a dimmer settings so that you can continue to use it in the evenings when you don’t want the light as bright.

Nighttime Solutions

In the evening we need to gradually reduce that amount of light that we see so that our melatonin levels can naturally rise and fall asleep at bedtime. This is probably the hardest change because people like to watch TV before they go to bed, and sometime while laying in bed. The TV is probably the worst thing before falling asleep because of the bright light that it puts out and the constant rapid flashing between bright and dark. It is probably best to turn off the TV, computer, tablet and any other backlit devices at least an hour before you go to bed.

For sleeping, get your bedroom as dark as possible. Dark curtains will better block the light from outside. Unplugging night lights and electronics, or at least putting something over the displays will also help to darken the room. If you can’t darken the room then using a sleep mask will block the light from your eyes.

The Nikken sleep mask, the Kenko PowerSleep Mask, is a great choice. It is comfortable for sleeping, doesn’t get hot, blocks out light very well, and has magnets that help to ease tension around your eyes. I use mine every night.

Disclaimer and Disclosure

I am not a doctor and this post is not intended as medical advice. I have addressed only one of many possible reasons for poor sleep. Some sleep issues can be due to medical conditions. If you think you have a medical reason for poor sleep then please see your doctor. I am an independent Nikken distributor, so I may earn some income if you order from Nikken through the links on this page.