Listen to an audio transcription of this post
The Blue Light Effect: Can It Really Influence Your Sleep Cycle?
It's time to start winding down again, and that comfortable pillow and bed are calling to you. So, you settle into bed with your tablet or phone, or you turn on your favorite show to unwind.
These common bedtime routines put you in the 90% of people who use an electronic device before going to bed. Problematically, that blue light could be negatively impacting your ability to sleep.
Blue light is there whether you're browsing through social media or you're watching a movie to nod off. The reality is that too much screen time and blue light exposure isn't good for you. Your circadian rhythm could fall out of alignment, and you may not feel as awake and energetic as you'd like in the morning as a result.
Understanding Blue Light and the Visible Light Spectrum
Blue light is just one kind of light on the visible light spectrum. It's unique because it vibrates between 380 and 500 nanometers, the shortest wavelength humans can see. At that short wavelength, blue light also has a high amount of energy.
Every color you can see is on the visible light spectrum, but blue is the only color that the human eye cannot filter. As a result, this high-energy visible (HEV) light has the ability to pass into the eye and straight to the retina.
When Are You Exposed to Blue Light?
There is exposure to blue light all the time. It comes from natural and unnatural sources such as:
Fluorescent and LED lights
Natural sources are usually of less concern versus blue light from digital devices. Lights from your digital devices are much closer to the eyes. The cumulative impact of using your devices every day can have a negative impact on the eyes, such as by causing digital eye strain.
Pros and Cons of Blue Light Exposure
Blue light isn't all bad, it actually benefits our brains in a number of ways. But you need to think about what blue light is good for to realize why it's not a good idea to be around it at night.
Blue light frequency helps:
Boost memory and cognitive function
Regulate your circadian rhythm
While it is the case that blue light is necessary for good health, the same benefits can lead to trouble at night.
Blue light affects your alertness, for example. If you want to head to sleep, looking at your phone or having a computer in the room could make it harder for you to drift off. This is due to a negative impact on your sleep-wake cycle (circadian rhythm).
A study by Harvard researchers found that 6.5 hours of blue light exposure suppressed melatonin. That's the hormone that helps time your circadian rhythm. The suppression lasted for around twice as long as green light exposure at a comparable brightness. Additionally, the blue light exposure ended up shifting the subjects' circadian rhythms by twice as much. Overall, there was a three-hour change instead of a 1.5 hour change (green light).
On top of that, remember that memory and brain function are also boosted with blue light exposure. While that's great during your work day, the same isn't true when you're trying to get to bed at night.
Fortunately, putting down those digital devices soon enough in the evening can help you avoid the blue light that keeps you awake. And, as a bonus, it prevents digital eye strain and too much screen time.
The Long-Term Impact of Blue Light Exposure
It's worth stating that blue light exposure is a public health concern. Overexposure to blue light can lead to all kinds of health problems that may hinder your daily activities. A survey found blue light could cause headaches, blurry vision, sleep disruptions, and dry eyes.
Additionally, the UC Davis Eye Center states that regular exposure to blue light can lead to vision problems. Some include macular degeneration and damage to the retinal cells. Eye cancer, cataracts, and other issues may also arise as a result of exposure to blue light over time.
Will Blue Light Blocking Glasses Help?
Blue light-blocking glasses have blue light-filtering lenses. These may help reduce the amount of blue light absorbed into the retinas. It's believed (though there is not yet much proof) that using blue light glasses could help:
Enhance your visual performance during the day
Help improve sleep-wake cycles
Preserve macular (eye) health
Studies into the helpfulness of blue light glasses are still ongoing. Other options, such as cutting back on excessive screen time, may be a better option to reduce exposure to blue light.
How to Cut Back on Exposure to Blue Light
An upside of blue light is that how much you're exposed to greatly depends on what you do each day. Changing your routine even a little bit can have a massive impact on blue light exposure. Additionally, it will help prevent eye strain, sleep disorders, visual discomfort, and more.
What can you do to reduce how much blue light your eyes absorb each day?
Cut Down on Your Screen Time
Cut back on screen time. Take regular breaks from blue light-emitting sources to give your eyes a break. It's particularly important to avoid blue light at night since exposure could lead to more trouble getting to sleep.
Use Built-In Technology
Have you noticed that you can dim your phone's screen? Did you realize that you can switch the color of your monitor or the lighting of your television set?
Each of these settings can help alter the light coming from the digital device. Choosing "read" mode or a warmer temperature can help minimize blue light exposure in the evening.
Buy Blue Light Filtering Screen Protectors
Blue light filtering screen protectors are now available and automatically filter blue light. All modern monitors usually have a blue light filter built in, so check your monitor's settings before you purchase an external filter.
Remember the 20-20-20 Rule
The 20-20-20 rule is great for your eyes. The rule states that for every 20 minutes of screen time, you should look at something at least 20 feet away for approximately 20 seconds. For example, if you're working on your computer in your office, set a timer to go off in 20 minutes. Then, look out your window at something around 20 feet or more from you. Focus on it, and keep looking for 20 seconds or longer.
After doing this, your eyes should feel slightly better. Taking these breaks is essential for good eye health.
Try Blue Light Glasses
If you're working on a digital device that doesn't have a blue light protector built in, you'll want to consider something like blue light glasses. These help you avoid getting more blue light than you need.
Visible blue light passes into the eyes and retina easily with normal glasses. Blue light glasses could help reduce how much blue light gets in and encourage your body's circadian rhythm to stay on track. And, for an added perk, they often look cool, too.
Adjust Your Monitor or Screen Time
Instead of thinking of screen time as something you track for time's sake, think of it as "blue light screen time" and something you track for your health. If you don't have computer glasses or blue light filters handy, you can simply cut down on the amount of time you look at screens.
Whether that means taking breaks from devices throughout the day or after dinner, the result is less blue light entering your eyes.
How much screen time is too much? Reid Health suggests no more than two hours of screen time outside work hours. That adds up to a standard 10 hours a day. Need more time? Try adjusting your monitor. Put on blue light glasses, and have a hard cut-off time each night.
Try Anti-Reflective Lenses
Blue light damages your eyes when it's in excess. For people who already wear glasses, one simple fix is to try anti-reflective lenses. Anti-reflective lenses don't block blue light. However, they do block glare that could contain additional blue light that has bounced off objects.
Managing Blue Light Exposure Helps You Get the Best Sleep Possible
At Blissy, we want you to get the best rest you can, and we know that blue light can be a factor in sleep deprivation. We encourage you to try to adjust your screen time and swap out fluorescent lights for warmer bulbs. By doing so, you can minimize exposure to blue light in your home.
The reality is that you can't stop all blue light from impacting you. Still, taking simple steps like turning off your electronic devices at night or wearing blue light protection can help. Taking these steps during the day can make it much easier to fall asleep at night.
A good night's sleep awaits with simple changes. If you're having a hard time getting to sleep, start by taking a look at your sleep hygiene. Get it on track (we have some ideas for you!), make your bedroom comfortable with silk pillowcases and use light-blocking blinds. All of these steps make it easier to cut out unnecessary sources of blue light.
- Are electronic devices impacting your sleep? (n.d.). UCLA Health. https://www.uclahealth.org/news/are-electronic-devices-impacting-your-sleep#:~:text=If%20you're%20one%20of,it%20harder%20to%20fall%20asleep.
- Blog | How Much Screen Time is Too Much for Adults? (n.d.). Reid Health. https://www.reidhealth.org/blog/screen-time-for-adults#:~:text=What's%20a%20healthy%20amount%20of,spent%20participating%20in%20physical%20activity.
- Grieco, E. (2021, July 7). Anti-Reflective Coating vs. Blue Light Coating | SportRx. SportRx.com - Transforming Your Visual Experience. https://www.sportrx.com/blog/anti-reflective-coating-vs-blue-light-coating/
- Harvard Health. (2020, July 7). Blue light has a dark side. https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side#:~:text=Harvard%20researchers%20and%20their%20colleagues,as%20much%20(3%20hours%20vs.
- How blue light affects your eyes, sleep, and health. (2022). UC Davis Health. Retrieved November 14, 2023, from https://health.ucdavis.edu/blog/cultivating-health/blue-light-effects-on-your-eyes-sleep-and-health/2022/08
- Jos. (2022, August 23). What is a blue light filter? Coolblue. https://www.coolblue.nl/en/advice/what-is-a-blue-light-filter-in-a-monitor.html
- Melatonin: What You Need To Know. (n.d.). NCCIH. https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know#:~:text=What%20is%20melatonin%20and%20how,night%20can%20block%20melatonin%20production.