How Light Exposure Impacts Your Sleep + What to do About it

Jerry F. Scarlato
7 min readMar 10, 2020

Sleep is one of the most overlooked factors to improve when it comes to better health. You’ve been told more than once that, for optimal rest, you should get 8 hours of sleep. However, this number is truly arbitrary. And while it does make sense for most of us to try to get between 7 and 9 hours of sleep regularly, there is a more important factor for sleep health.

Statistics show that a decrease in sleep quality can increase your risk of heart disease by 70%…yes, 70%!! That’s an insane number. This means it makes sense to figure out how you can start to improve how well you’re sleeping how much you’re sleeping. In turn, if you start to improve your sleep quality, you might just notice that your sleep quantity is going up as well.

Now, there are a lot of factors that play into the quality of sleep that you might be getting. The comfort of your bed, the noise in the neighborhood, the softness of your pillow, and what you have going on tomorrow are a few possible culprits. However, there is one factor that stands out as far as its impact on sleep quality, and that’s light. Yes, light exposure impacts your sleep.

To help bring some clarity as to how this happens, let’s start with a short story about our ancestors.

Let There Be Light…

For hundreds of thousands of years, our ancestors woke up and fell asleep to the rise and fall of the sun. Although artificial light in the form of candles has been around for about 5,000 years, it’s only been about 300 years since light has become so omnipresent. And although candles certainly played an important role in keeping our houses lit up for a major part of our modern evolution, the flickering light coming from fire doesn’t hold a candle (pun intended) to the effect that modern, electrical-based lighting has on our health.

To help you understand this concept a bit more, let’s take a look at the types of light that we run into throughout our day. Then we can see what that light does to our body’s to hinder or promote better sleep. To start with, there is, of course, natural light. Natural light comes from the sun. As I’ve mentioned, for millennia the sun was the primary “alarm clock” for our ancestors. It let them know when it was time to wake up and when it was time to go to sleep.

However, the sun can be thought of as more than just an alarm clock. Our bodies actually are naturally connected to the cycle of the sun via the circadian rhythm. Your circadian rhythm is the body’s natural cycle of getting tired as the sun is setting and waking up as the sun is rising. This cycle is regulated primarily by a hormone called melatonin. As the sun sets, the body senses that it’s becoming dark and starts the production of melatonin to make you sleepy. And as the morning approaches, your melatonin levels naturally begin to decrease as the sun rises to increase your wakefulness.

How Light Exposure Impacts Your Sleep Health

In the society we live in today, there are many factors that can inhibit this natural cycle of waking and sleeping. Such as the second kind of light we’ll talk about, and that’s artificial light. Artificial light is simply light we have produced in some way. It might come from a street light, your cell phone, or even car lights.

These are the lights we’re surrounded by on a regular basis, including our digital devices. Because they are such a staple in our lives today, it’s hard to think of living a day without the ability to simply flip a switch and turn a light on. The truth is, this artifical light could be wreaking havoc on your sleep, and also on your overall quality of health.

For example, recent studies have shown that exposure to LED lights not only has a negative impact on sleep quality, but can also lead to increased risk of cancer, cardiovascular disease, type 2 diabetes, and obesity. When it comes to being directly related to sleep, the biggest culprit to our lowering of sleep quality is blue light exposure.

The Blue Light Blues

Blue light is the type of light that comes from our devices. This includes TVs, tablets, laptops, and, yes, your beloved phone. The truth of the matter is, blue light is killing your sleep, killing your eyes, and likely slowly killing your brain.

Remember when we talked about melatonin production and it controlling your natural sleep cycle? Well, blue light suppressed the production of melatonin at night. Because of this lower melatonin production, you have lower sleep quality because your hormone levels are not where they should be to keep you asleep throughout the night.

3 Ways to Utilize Light to Improve Your Sleep Health

So, now that you have an idea of the different types of light and how they impact your health, it’s time to see how you can improve your light exposure. Let’s take a look at how you can start to adjust your day to improve your sleep quality and thereby improve your health and vitality.

Some of these adjustments may be simple. However, as it’s worth remembering, you must do this stuff every day in order for it to have the greatest impact on your longevity.

#1) Get 10 Minutes of Morning Sun

The effects of early sun exposure and sleep quality are abundant. Which doesn’t make much sense considering…well…you’re getting sun in the morning. However, a research review in 2008 showed how morning sun exposure led to improved vitamin D and melatonin production. These 2 variables were linked to a improvement in certain diseases, including:

  • Hypertension
  • Heart disease
  • Asthma
  • Multiple sclerosis
  • Infections

All of this simply by exposing yourself to sun in the morning. Why morning sun you ask? Because the morning sun is less intense than the daytime sun. This lowers your exposure to harsh rays that may be penetrating your skin during the day (not that you shouldn’t be out in the sun during the day. That’s a story for a different article). So, shoot to get outside for at least 10 minutes between 7:00am and 10:00am.

#2) Don’t Wear Sunglasses

GASP!! Don’t wear sunglasses?! Yes, that’s correct. I’m strongly encouraging you to not wear sunglasses on a regular basis. This doesn’t mean that you shouldn’t wear them at all. It just means that you should let your eyes be free of cover during your normal daily routine.

This is because your eyes need natural sun exposure in order to function properly. Light waves coming in from the sun help to promote healthfulness in your eye. There are about 1500 wavelengths that your eye needs to be exposed to in order to function properly throughout life.

With that said, you can wear your glasses when doing activities that increase the intensity of the suns rays, including snow skiing or water skiing. Other than that, you simply don’t need to protect your eyes as much as you are led to believe. I have never worn sunglasses on a regular basis. As a 35 year old with 20/10 vision, which is technically “perfect”, I believe that this is partly why I’ve been able to maintain such good eyesight.

So, instead of fretting over sunglasses, improve your nutrition to build up your body’s natural sun blocking abilities. Certain antioxidants, such as astaxanthin found in seafood, have been proven to help protect your body from the damaging effects of sun rays.

#3) Eliminate Blue Light at Night

The final strategy we’ll talk about is likely the most important (although the previous 2 are certainly game changers if you use them correctly). Blue light exposure at night is the killer of quality sleep. This is primarily through the process described above in the lowering of melatonin production. To lower your blue light exposure at night, there are a couple of things you can do.

First, if you really want to dive in head first, you can eliminate all screens from your nighttime routine within 2 hours of bedtime. That means no TV, no tablets, no laptops, and no phones. This is going to have the biggest impact on healthy melatonin production and on improving your sleep quality. Instead of watching TV or staring at your phone, I strongly suggest putting together a nighttime routine such as stretching, journaling or planning your day.

Second, for those of you who have a hard time letting go over your devices at night, use blue light blocking software such as Iris, or blue light blocking glasses to lower the effects of blue on your sleep. Iris will adjust your screen color to only allow your screen to emit certain colors that will not impact your melatonin production, while the glasses will do essentially the same thing.

Don’t overlook the importance of regulating your natural and artificial light exposure to improve your sleep quality. Not only will this be hugely beneficial to your immediate health and productivity, it will also play a major role on your quality of life and longevity moving forward.



Jerry F. Scarlato

Entrepreneur, Fitness Coach, Performance Specialist, Speaker, Author, cook, endless learner. Check more out: