Bedroom LED Lights.

Is it Safe to Sleep With LED Lights On? (5 Health Risks)

by
Dr-Babar-Naeem.

This article was written by Dr. Babar Naeem (MBBS, MRCPCH) – a licensed and practicing medical doctor – to ensure maximum factual accuracy and unique content.

LED lights are a great way to transform the ambiance of your bedroom.

But is it safe to sleep with LED lights on?

It’s physically safe to sleep with LED lights on as long as the wires aren’t pinched. However, sleeping with LED lights on can cause sleep disruption because the light wavelengths can suppress melatonin production, increase sleep latency, disrupt REM sleep, and cause overstimulation.

So what’s the safest way to sleep with LED lights on if you don’t want to turn them off at night?

To sleep safely with LED lights on, make sure the wires aren’t pinched or causing a hazard; and choose a red LED light instead of blue or white, turn down the brightness, wear an eye mask or use blackout blinds, and turn off other electronics in the room to minimize sleep disruption.

In the rest of this article, I have used my medical knowledge and access to scientific literature to explain in more detail the risks of sleeping with LED lights on – specifically in regards to sleep disruption.

Related: click here to discover 22 bedroom LED lighting ideas.

The 5 Risks of Sleeping With LED Lights On

Here are the 5 main drawbacks to sleeping with LED lights on:

1: Decreased Melatonin Secretion Disrupts Sleep

Exposure to LED lights at night reduces the production of melatonin which can make it harder to get to sleep and stay asleep.

Melatonin Regulates Your Sleep-Wake Cycle

Melatonin is a sleep hormone that is secreted from a special gland in the brain, called the pineal gland.

Production of melatonin is increased when there is darkness and suppressed in the presence of light.

Melatonin is crucial for regulating the internal master clock (circadian rhythm) that controls the sleep/wake cycle.

The presence of increased melatonin levels in the body sends a signal to the brain to stimulate a set of neurons that activate the sleeping process.

When the level of melatonin is decreased in the body, the master clock sends a signal to keep us alert and awake.

In this way, melatonin controls wakefulness and sleep; that’s why this cycle is called the sleep/wake cycle.

LED Lights Can Disrupt Your Sleep-Wake Cycle

Researchers in Switzerland described melatonin as a hormone that opens the gates of sleep [1].

LED light has a short wavelength of 460 nm, and synchronizes with the circadian rhythm.

Moreover, the internal clock is most vulnerable to light in the hours before bedtime, as light has the capacity to reset it [2].

When we sleep with LED lights on, our circadian rhythm senses that there is light.

As a result, the production of melatonin is delayed, impaired, or reduced.

Decreased melatonin levels keep us awake, and it becomes very difficult to sleep.

Learn more about melatonin supplements here.

2: Prolonged Sleep Latency Means it Takes Longer to Get to Sleep

Sleep latency is the amount of time that a person takes to fall asleep after getting into bed.

A normal person takes about 10-20 minutes to fall asleep [3].

Sleep latency is a very important measure, as it tells us whether we are getting enough sleep or not.

It is not always possible for a person to recognize insomnia or narcolepsy just by the symptoms experienced so sleep latency provides an objective measure of the quality of sleep.

If a person has a very short sleep latency (less than 8 minutes), it shows increased sleepiness that may be due to sleep deprivation or a sleeping disorder.

On the other hand, a prolonged sleep latency (greater than 20 minutes) means a person is unable to initiate the process of sleep and has insomnia.

LED Lights Can Keep You Awake Even After Switching Them Off

LED lights at night have the tendency to prolong sleep latency, due to a lot of factors – such as disrupting circadian rhythm, decreasing melatonin production, and improving vigilance [4].

Researchers at the Department of Community Health and Epidemiology, Japan did a very interesting study to test the effect of nighttime light exposure on sleep latency.

They measured light exposure at night, and studied its effects, measuring sleep latency with a simple device called a wrist actigraph.

They found that exposure to light in home settings at night increases the latency of sleep [5].

Therefore, exposure to LED lights right up until bedtime can make it harder to fall asleep because the disruptive effects on the sleep-wake cycle don’t go away immediately.

Discover the 8 hidden dangers of sleeping in headphones here.

3: Decreased Rapid Eye Movement (REM) Sleep

When we sleep, the brain goes through different phases, and all of them are important for our health.

These stages can be divided into two phases: REM and Non-REM sleep.

Non-Rapid Eye Movement (Non-REM)

Non-REM sleep starts first after we go to bed, and represents a transition between wakefulness and sleep.

REM Sleep

REM sleep, also known as the ‘paradoxical sleep’, starts approximately 90 minutes after falling asleep.

It has unique physiological characteristics, like low muscle tone, increased heart rate, irregular breathing, rapid movements of the eye, and dreams.

This phase resembles the wakefulness state, and the activity of the brain is way higher than during the other stages of sleep.

REM sleep occurs in intervals.

The first period is usually about 10 minutes and the duration of the subsequent intervals increases.

REM sleep is very important for relaxing the body and stimulating the areas of the brain associated with learning.

Decreased REM sleep can result in fatigue, depression, short temper, inattention, and poor performance [6].

Studies have shown that exposure to LED lights at bedtime decreases the rapid eye movement stage, and causes insomnia [7].

Click here to discover how sleep paralysis occurs.

4: Increased Alertness

Exposure to LED lights at night keeps us more alert.

Alertness is characterized by a low level of fatigue, high wakefulness, high sensitivity to external stimuli, and increased environmental awareness.

Although this is important for us to increase our work performance, it can cause sleep disturbance if it occurs at night.

The visual effects of lights are widely known, as they are sensed by photoreceptors in our eyes.

But the nonvisual effects of light on the body have recently been explored.

Alertness is strongly influenced by exposure to LED light.

During the day, exposure to increasing light keeps us awake, while lower alertness occurs at night.

There are many mechanisms by which light affects our alertness.

Exposure to light stimulates an area of the brain called the Supra Chiasmatic Nucleus (SCN), which is located in the hypothalamus.

This area controls our adaptation to our surroundings, by controlling alertness.

When SCN is activated, it decreases the inhibitory neurotransmitters in the body and increases excitatory hormones.

Production of adrenaline and norepinephrine is also increased, and both of these have a very strong effect on arousal and wakefulness.

The other mechanisms by which exposure to light increases alertness are by affecting the circadian rhythm, and decreasing melatonin production [8].

There is a famous physiological review on the ‘Alerting Effects of Light’, published in ELSEVIER, that provides a detailed discussion about the effect of exposure to light on alertness [9].

The Center for Disease Control and Prevention (CDC) also recommends using light to manage alertness.

They advise that if you are feeling drowsy, and want to work, you should move closer to a light source.

Find out if sleeping with earbuds at night causes cancer.

5: Increased Mental Health Problems and Mood Disorders

Another very important, indirect way in which exposure to LED lights at night causes sleep disturbance is through increased mental health problems.

This occurs due to the effect of light on the secretion of neurotransmitters in the brain.

The incidence of psychiatric problems, like depression, anxiety, and bipolar disorders is increased.

All these disorders result in poor quality of sleep.

Sleep disturbance further worsens these disorders, and a vicious cycle begins [10].

Click here to discover the risks of sleeping with AirPods in.

How to Sleep Safely With LED Lights On

If you would prefer to sleep with LED lights on at night, then here are 5 tips to follow:

1: Choose a Red Color LED Light to Reduce Overstimulation

Red-colored LED lights are best for the bedroom because they aren’t as disruptive as blue or white-colored lights – which promote alertness.

For a long time, it was thought that all artificial lights have the same effect on sleep.

However, recently, scientific research has shown a different side of the story.

The color of light not only affects the visual appearance of a room but also has very important psychological and physiological effects.

Korean researchers conducted a study and demonstrated that a change in the color of the light has a significant effect on the onset of sleep [11].

The difference in the effects of different colors on sleep is due to the difference in wavelength.

Red Light Can Be Soothing

Red light has a soothing effect on your mood and promotes sleep by increasing the secretion of melatonin and relaxing the muscles of the body.

Anti-oxidant (glutathione) levels and energy production are also increased by red light.

The wavelength of red light is around 620-750 nm. 

Researchers at the China Institute of Sports Science, Beijing, investigated the effects of red light on the quality of sleep and performance of basketball players.

They found that athletes who slept under red light had increased secretion of melatonin, and improved quality of sleep when compared to those who didn’t.

Endurance performance in female basketball players was also improved [12].

Blue Light Can Wake You Up

Blue light has high energy waves and wavelengths from 450 to 500 nm.

It keeps us alert and aroused, which is a good thing during the day, but becomes harmful at night.

If we are exposed to blue light at night, our circadian rhythm is disturbed, and the secretion of melatonin is decreased.

This is because our brain cells are more sensitive to the blue light wavelength.

Blue light also has a tendency to negatively affect our sleep.

A recently conducted study demonstrated that patients exposed to blue light had more chances of developing anger, depression, confusion, dejection, and hostility.

The researchers, therefore, recommended using colored screens to block blue light for such patients [13].

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2: Decrease the Brightness to Lessen Sleep Disruption

Decreasing the brightness of your LED lights can reduce the amount of disruption they cause to your sleep.

The brightness of light is measured in lux (luminous flux per second).

Daylight has a brightness of 10,000 to 25,000 lux, while the average living room has around 50 lux.

Light with increased brightness keeps the body alert and awake.

When it’s dark, a signal is sent to the brain to increase the production of the sleep hormone, melatonin.

Melatonin initiates the sleep process by relaxing smooth muscles, lowering body temperature, and activating the parasympathetic system.

Lowering the brightness or luminosity of the LED lights will improve your chances of sleeping comfortably.

Hence, pitch darkness is ideal for sleep, as it minimizes disruptions.

Sleeping with LED lights on causes frequent arousal and shallow sleep [14].

Light can even pass through closed eyelids, and suppress the secretion of melatonin [15].

If it is not possible for you to create darkness in the bedroom, or you want some light, so that you can go to the bathroom at night, then you should minimize the brightness of that light.

You should dim the lights for at least one hour before going to bed.

Dimmer switches and dimmable bulbs are easily available on the market.

Click here for 19 ways to black-out your room for better sleep.

3: Wear an Eye Mask to Block Out the Light

Eye masks offer a cheap and effective solution for blocking out environmental light.

Light disrupts our normal sleep/wake cycle by creating a false signal in the brain that it’s not time to sleep.

So it’s necessary to switch off all the lights to maximize the chances of getting a night of high-quality sleep.

But, there are a lot of reasons for which some people are not able to turn off the lights.

Some are simply afraid of the dark, and others are subjected to lights in nearby rooms or houses.

Regardless of the reason, eye masks – or sleep masks – provide us with a chance to enjoy the beneficial effects of darkness on our sleep.

There are a lot of different eye masks available on the market, and you should choose one wisely.

The mask should be soft, comfortable, and lightweight.

The appropriate size is also important, as a tight mask can cause a lot of discomfort, while a loose one will not filter out the light.

Find out if hot chocolate can help you sleep or not here.

4: Turn Off Electronics at Bedtime

Electronic devices have become an important part of our lives, but they have the potential to cause sleep disturbance.

These devices emit a short-wavelength blue light, which decreases the production of melatonin.

They also keep us alert and delay the onset of sleep.

A study published in the British Medical Journal researched the effects of electronic device usage on 9846 adolescents.

The researchers found that the use of electronic devices during the day and night prolonged sleep latency, shortened sleep duration, and increased sleep deficiency [16].

I always recommend that my patients stop the use of all electronics, at least one hour before going to bed.

The use of electronic devices during the day and in the evening should be minimized.

The bedroom should be made a screen-free zone.

Try these 10 tips for reducing tiredness after staying up late.

5: Use Blackout Blinds and Curtains in the Bedroom

A dark environment is essential to getting a night of good quality sleep, as it is in line with our internal biological clocks.

Blackout blinds help us create a dark environment, by filtering out all the light pollution that can cause sleep disruption.

They also reduce environmental noise, which is another cause of sleep disturbance.

Another advantage of blackout curtains is that they form an insulating layer, and prevent the bedroom from becoming too hot or too cold.

Blackout curtains are also useful for those people who work at night and need to sleep during the day.

These curtains can create a night-like environment by filtering out the noise and light.

I advise my clients to lift the curtains in the morning, as exposure to light will make them alert and fresh.

Try these 7 tips for making a north-facing bedroom feel warmer.

Conclusion: Avoid Sleeping With LED Lights On

Sleeping with LED lights on causes sleep disturbance by disrupting the natural sleep/wake cycle.

To counter this problem, you should dim the lights at night, and turn off other sources of light.

The use of eye masks and blackout curtains is also helpful.

Up next: 10 ways to sleep better after exercising.

References

[1] C. Cajochen, K. Kräuchi, and A. Wirz-Justice, “Role of Melatonin in the Regulation of Human Circadian Rhythms and Sleep,” J. Neuroendocrinol., vol. 15, no. 4, pp. 432–437, Apr. 2003, doi: https://doi.org/10.1046/j.1365-2826.2003.00989.x.

[2] C. Cajochen et al., “Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance,” J. Appl. Physiol., vol. 110, no. 5, pp. 1432–1438, Mar. 2011, doi: 10.1152/japplphysiol.00165.2011.

[3] D. W. Jung, S. H. Hwang, G. S. Chung, Y.-J. Lee, D.-U. Jeong, and K. S. Park, “Estimation of Sleep Onset Latency Based on the Blood Pressure Regulatory Reflex Mechanism,” IEEE J. Biomed. Heal. Informatics, vol. 17, no. 3, pp. 539–544, 2013, doi: 10.1109/JBHI.2013.2257816.

[4] L. Tähkämö, T. Partonen, and A.-K. Pesonen, “Systematic review of light exposure impact on human circadian rhythm,” Chronobiol. Int., vol. 36, no. 2, pp. 151–170, Feb. 2019, doi: 10.1080/07420528.2018.1527773.

[5] N. K. Kenji Obayashi , Keigo Saeki, Junko Iwamoto, Nozomi Okamoto, Kimiko Tomioka, Satoko Nezu, Yoshito Ikada, “Effect of exposure to evening light on sleep initiation in the elderly: a longitudinal analysis for repeated measurements in home settings,” 2014, doi: 10.3109/07420528.2013.840647.

[6] J. M. Siegel, “Chapter 10 – REM Sleep,” M. H. Kryger, T. Roth, and W. C. B. T.-P. and P. of S. M. (Fourth E. Dement, Eds. Philadelphia: W.B. Saunders, 2005, pp. 120–135.

[7] A.-M. Chang, D. Aeschbach, J. F. Duffy, and C. A. Czeisler, “Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness,” Proc. Natl. Acad. Sci. U. S. A., vol. 112, no. 4, pp. 1232–1237, Jan. 2015, doi: 10.1073/pnas.1418490112.

[8] R. Lok, K. C. H. J. Smolders, D. G. M. Beersma, and Y. A. W. de Kort, “Light, Alertness, and Alerting Effects of White Light: A Literature Overview,” J. Biol. Rhythms, vol. 33, no. 6, pp. 589–601, Dec. 2018, doi: 10.1177/0748730418796443.

[9] C. Cajochen, “Alerting effects of light,” Sleep Med. Rev., vol. 11, no. 6, pp. 453–464, 2007, doi: https://doi.org/10.1016/j.smrv.2007.07.009.

[10] M. Bauer et al., “The potential influence of LED lighting on mental illness,” World J. Biol. Psychiatry, vol. 19, no. 1, pp. 59–73, Jan. 2018, doi: 10.1080/15622975.2017.1417639.

[11] S. Lee and D. Kim, “Effect of Color Light Stimulation Using LED on Sleep Induction Time,” J. Healthc. Eng., vol. 2017, p. 6030268, 2017, doi: 10.1155/2017/6030268.

[12] J. Zhao, Y. Tian, J. Nie, J. Xu, and D. Liu, “Red light and the sleep quality and endurance performance of Chinese female basketball players,” J. Athl. Train., vol. 47, no. 6, pp. 673–678, 2012, doi: 10.4085/1062-6050-47.6.08.

[13] S. Han and D. Lee, “The effects of treatment room lighting color on time perception and emotion,” J. Phys. Ther. Sci., vol. 29, no. 7, pp. 1247–1249, Jul. 2017, doi: 10.1589/jpts.29.1247.

[14] J. R. Cho, E. Y. Joo, D. L. Koo, and S. B. Hong, “Let there be no light: the effect of bedside light on sleep quality and background electroencephalographic rhythms,” Sleep Med., vol. 14, no. 12, pp. 1422–1425, 2013, doi: https://doi.org/10.1016/j.sleep.2013.09.007.

[15] M. G. Figueiro and M. S. Rea, “Preliminary evidence that light through the eyelids can suppress melatonin and phase shift dim light melatonin onset,” BMC Res. Notes, vol. 5, p. 221, May 2012, doi: 10.1186/1756-0500-5-221.

[16] M. Hysing, S. Pallesen, K. M. Stormark, R. Jakobsen, A. J. Lundervold, and B. Sivertsen, “Sleep and use of electronic devices in adolescence: results from a large population-based study,” BMJ Open, vol. 5, no. 1, p. e006748, Jan. 2015, doi: 10.1136/bmjopen-2014-006748.

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