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7 Tips for Managing Light Exposure

June 1st, 2017

Light can improve or diminish your sleep health depending on the timing of when you expose yourself to it. The circadian rhythm, our body’s internal clock that regulates sleep-wake patterns and other processes, primarily relies on light and darkness to stay in sync with the 24-hour cycle.  

When you expose yourself to light during the day, it signals to your brain that you should be awake and alert, but it can disturb your body’s wind-down process at night.  

Here’s a low down of what light is, how exposure to it affects sleep, and ways to manage this exposure. 

What Is Light Exposure?

Experts describe light as the “strongest time cue to the circadian clock that keeps these rhythms entrained to the 24 h day.” In other words, light helps the body’s clock run on 24 hours.  

The sun and artificial lights (light powered by electricity) are sources of light that impact the circadian rhythm. The time we expose ourselves to these light sources can influence our body’s ability to rest and get deep sleep or be active. 

Unlike the sun, which only comes out during the day and goes down at night, we can stay exposed to artificial light 24/7. And when this happens, it can put our circadian rhythm out of sync with the 24-hour clock. This desynchronization might cause adverse effects on our health, including our sleep. 

How Does Light Exposure Affect Sleep?

The brain releases melatonin—a hormone that supports the circadian rhythm—in response to darkness. The body starts producing melatonin in response to darkness and reduces its production in response to brightness, particularly the early morning. Melatonin, in part, regulates our circadian rhythm in preparation for sleep.  

Light exposure at night suppresses melatonin production, disrupting the body’s cue to relax and wind down for sleep. Evidence suggests that low melatonin production is associated with health conditions like cancer, heart diseases, diabetes, obesity, depression, cognitive dysfunction, and sleep deprivation.  

According to research, our body is maximally sensitive to shorter wavelength blue light. Unfortunately, many devices like laptops, phones, tv, tablet, and some home lighting, emit blue light. 

The Centers for Diseases Control and Prevention (CDC) explains that exposure to bright light two hours before bedtime shifts sleep time and wake time to later. In contrast, morning sunlight shifts sleep time and wake time to earlier. In addition, bright light of all wavelengths might cause us to feel more alert, thus limiting our ability to wind and prepare for sleep. 

It’s no wonder that a 2013 study observed that electric light, which is available to humans round the clock, reduces our exposure to sunlight and increases our exposure to artificial light at night which can contribute to circadian rhythm misalignment and late sleep times.  

Similarly, a 2019 study suggests that exposure to even low-intensity blue light may impair sleep health by disrupting sleep quality, circadian rhythm, and sleep cycle durations. Another study found that reducing light exposure at sundown may improve sleep schedule and quality. 

Essentially, light exposure or insufficient darkness at nighttime can confuse and disrupt the body’s internal clock and interfere with sleep quantity and quality. 

But it’s not just light before bed that impacts sleep – light exposure during sleep might also cause health issues. For example, a recent study found that even moderately dim light that is left on overnight can impair our cardioembolic system by increasing our nighttime heart rate and increasing insulin resistance. 

Tips For Managing Light Exposure

Sunlight supports our circadian rhythm’s pacing as it rises during the day, helping us stay alert and active when we should, and goes down in the evening, letting our bodies slow down and rest.  

Artificial light also keeps us active and awake, just like sunlight. But unlike sunlight, it’s available to us 24/7, even when we should be relaxing and getting ready for bed.  

Round-the-clock exposure to artificial light can throw off your circadian rhythm and sleep schedule. Here are tips that may help you manage your light exposure.  

1. Install Window Curtains or Black Out Blinds To Reduce Overnight Light 

One way to achieve pitch darkness after turning off all the lights in your bedroom is by having black-out window coverings heavy enough to block light and be well-fitted to prevent slivers of street light or early morning sunlight from filtering in. 

The body can better fall and stay asleep when the bedroom is completely dark. There are no lights to distract you or keep you awake. 

A 2021 study observed that enhanced curtains, with superior light-blocking, reduced daytime sleepiness and insomnia symptoms in sailors whose sleep quality is usually impaired by ambient light. 

2. Wear An Eye Mask 

An eye mask is a safe, non-addictive sleep aid that creates the ideal dark sleep environment, especially in circumstances where you have no control of the lighting in your room.  

An eye mask is inexpensive, and you can use them whenever and wherever you are. Just put them on once you’re ready to sleep and get complete darkness.  

A 2021 study found that eye masks and earplugs can significantly increase sleep duration, efficiency, and rapid eye movement (REM) sleep and reduce nighttime awakenings and sleep disturbances. Similarly, another study found that eye masks and earplugs improved subjective sleep quality in Intensive Care Unit (ICU) patients. 

3. Dim Lights Before Sleep

Studies indicate that room lighting significantly impacts melatonin production, and exposure during bedtime can suppress melatonin and affect sleepiness and sleep quality.  

Therefore before going to bed, try to dim your room lights or put them off entirely to protect you from the adverse effect of bright light on sleep and circadian rhythm. 

4. Remove Electronics From the Bedroom 

Another way to make your bedroom a sleep haven is by keeping digital devices, like your computer, tv, and other devices that produce lights from your bedroom at night.  

Evidence suggests that light exposure from electric lights and devices in the late evening hours can reduce sleepiness and disrupt sleep quality. 

5. Get Sunlight During the Day 

Sunlight helps keep the circadian rhythm in sync with the 24-hour time. Exposing yourself to sunlight during the day can help strengthen your sleep-wake cycles and promote sleep health. 

For instance, a 2015 study suggests that increasing indoor morning light exposure may improve sleep quality in older women. Likewise, a 2017 study found that older people may benefit from direct sunlight between 8 am and 10 am for better sleep quality.  

Experts recommend getting sunlight exposure, ideally in the first hour or two after waking up, to support your circadian rhythm, optimizing your sleep.  

6. Wear Blue Light Glasses 

Suppose you have to work with your computers or other blue-light-emitting devices until late evening hours. In that case, you can get blue light glasses to limit the amount of blue light you’re exposed to, given its impact on melatonin. A 2017 study suggests that wearing blue-light-blocking glasses two hours before bedtime significantly improved sleep quality, sleep duration, and insomnia symptoms compared to clear lenses.  

Likewise, a 2016 study found that the participants who used blue-blocking glasses while working on electronic devices two hours before bedtime had higher sleepiness and sleep efficiency and fell asleep faster compared to the control group. 

Another study found that using blue-blocking glasses increased subjective total sleep time, sleep quality, and melatonin levels. 

7. Limit Screen Time 

Blue light from your computers and phones can delay melatonin production and harm your sleep health when you expose yourself to them at nighttime. This is likely caused not only by blue light exposure, but also due to the stimulating nature of electronic device usage. A 2020 study found that heavy screen use is associated with difficulty falling asleep, midnight awakenings, shorter sleep time, and poor sleep quality. 

Researchers explain how screen-based light affects sleep thus: 

  • It may increase arousal and reduce sleepiness during bedtime. 
  • It can push back the circadian rhythm pace and delay sleep time, leading to lower sleep duration.  

Therefore, to reduce exposure to screen-based light, you can limit screen time in the evenings. You can cut down your screen time by  

  • Blocking or deleting apps your frequently visit around evening time. 
  • Turning off notifications to prevent you from constantly checking your device. 
  • Putting your phone in grayscale mode to make your screen less interesting to look at. 
  • Keeping your devices away from where you spend your evening time.  

Wrapping Up: How to Reduce Light Exposure 

Managing your light exposure can significantly improve your sleep health. If you’ve been experiencing poor sleep, you can start by prioritizing a dark sleep environment and reducing your exposure to blue light-emitting devices. Have more questions about lighting and better sleep? Tweet us @sleepscore today!  

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