How To Use Light To Improve Your Sleep

How To Use Light To Improve Your Sleep

sleep rhythm

Personal electronics and lights in your home may be two of the greatest impediments to a good night’s sleep.

Bright Light

Pardi describes the problem for us:

“We are not getting enough bright light during the day, and we’re getting too much of it in the evening.”

When this happens, our sleep cycle and circadian rhythms become de-synchronized, potentially leading to all kinds of problems such as cardiovascular disease, and metabolic impairment.

So how does light really affect our sleep?

Here’s the quick version: We have an area of cells in the brain called the suprachiasmatic nucleus that acts as our master clock and tells our cells what time of day it is.

These brain cells are very responsive to light entering the eye. The level and intensity of bright light tells the master clock to communicate certain commands to our cells. This is very important because our cells don’t do the same thing all day long. They have periods of rest and periods of higher activity.

When we don’t get enough sun during the day and too much light in the evening, our master clock falls out of sync and communicates mixed messages to our cells.

Melatonin and Light

Many of us have heard of melatonin often called the “sleep hormone”. It’s a powerful antioxidant as well as a reinforcer of our master clock so our body’s cells know what time it is and what activities to do.

Melatonin is highly sensitive and disrupted by the presence of bright white or blue light found in light bulbs, televisions, computers, tablets, and smartphones.

When we use these devices along with bright lights in the evening, the natural release of melatonin that occurs when the sun sets get pushed back. Then it becomes increasingly difficult to get to bed. We end up going to bed later and missing out on the quality and quantity of sleep we need to perform our best.

What type of lights should we use in the evening?

The cells in our eyes that send signals to our master clock respond differently to various wavelengths of light. Pardi tells us:

“Blue light or the light from normal light bulbs is the most stimulating. Light from televisions, ipads, and computers is stimulating enough to make your brain think that it’s still daytime. Even at low intensities, blue light is still stimulating. That’s why dimming lights is not as useful as changing the color of light you experience in the evenings.”


Pardi recommends that we use amber, orange, or red lights in the evening before bed. “Red light is not very stimulating. You could be in a room with red or amber light and it’s not going to have an equal effect on our cells.”

Using amber lights is simulating what humans experienced when we lived outside. “Dusk was the moment in the day where light shifted from blue to amber/red. Our bodies are used to getting this signal each day,” Pardi says.

But what about televisions, smartphones, tablets, and computers? Ideally, you would turn the television off an hour before bedtime in order to encourage sleepiness. If you’re using computers and electronic devices, we recommend you install f.lux (see more below).

How to develop a smart light rhythm

So if light is important to our master clock, the proper functioning of our cells and by extension our health, how do we develop what Pardi calls a smart light rhythm throughout the day?

We do this by getting enough bright light during the day and minimizing it at night.

How much bright light do we need during the day?

Pardi tells us that you get the maximal benefit of light in six hours of outdoor activity. But few of us will spend that much time outdoors.

Pardi says that “if you bundle each hour and look at the total effect, you’ll see that in the first hour of light you’ll get 80% of the benefit.”

So taking a morning walk and getting outside during our lunch break can give us much of the bright light we need to help rebalance and anchor our circadian rhythm. (And we now know that this means our brain is telling our cells what to do in the proper order.)

If you don’t get enough light during the day, light in the evening is much more likely to pull your rhythm forward. This means it might be harder to wake up in the morning, you may have more awakenings in the middle of the night, and it might be more difficult to go to bed the next night. Pardi describes this as putting your body in “perpetual jet lag.”

4 tips to dramatically improve your sleep.

Here are this week’s 4 tips. Add these together with last week’s tips and continue the April Clean Sleep Challenge!

#1 Get at least 1 hour of sun daily.

When you get a lot of light during the day, you anchor your circadian rhythms and are less vulnerable to light in the evenings. Remember, your daily of hour of light does not need to be all at once.

Tip: If you do spend most of your days indoors, there are ways to get more light exposure. Put a small blue light device on your desk to stimulate more alertness. Pardi says, “think of it as a cup of coffee.”

#2 Use amber lights in the evening.

Use inexpensive amber-toned light bulbs in the evening before bed. They filter blue/white light and create what Pardi calls “virtual darkness” or “circadian darkness.” Amber light still enters the brain so you can see but you’re not stimulating your circadian system to cause it to adjust.

When you use amber lights, you tell your body to produce melatonin and strengthen your circadian phase. You’ll feel the sensation of sleepiness and you’re more likely to go to bed and get a full night’s sleep.

#3 Add f.lux to your computer.

f.lux is a free program you install on your computer, smartphone, and tablet. It gradually reddens the light emitted from your screen after sunset. You’ll notice very quickly that it is more challenging to get work done in the evenings when you have it on. The white light emitted from your computer is no longer masking the tiredness you may already feel.

#4 Recognize how technology is affecting your sleep.

Lots of sleep experts tell us to turn off the television an hour before bed and not to bring our portable devices into the bedroom. We recommend this as well but we’re not convinced that many people will actually do it.

So we recommend you start by recognizing how using, for example, your tablet in bed may be truncating 45 minutes to an hour of very important sleep. If you must use your electronic devices in bed, be sure to install f.lux. You will still be stimulated to stay up by the content but not by the light.

Final Thoughts

Getting better sleep more consistently is one of the greatest tools you have for just about every area of your health.

We know you’ve heard that before. Like eating a clean diet and getting regular exercise, many important healthy practices are fairly mundane, so it’s easy to overlook them.

For many of us, before we did the Clean Program or the powerful Clean Gut Program, we thought we felt okay. But it wasn’t until after we completed a 21 day program that we realized how much better we could feel.

The same goes for sleep. We will not know how much better we can feel until we take a month to focus on sleep and find out how much quality rest we need to function best.

Let us know how your Clean Sleep Challenge is going on Facebook, Twitter, and Instagram. Use #cleansleepchallenge.