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Why is Blue Light Keeping me Awake?

Sleep is the main foundation of our health. It is equally as important as a healthy diet and exercise. However, we often tend to not give proper attention to how much sleep we get on a day-to-day. Not getting adequate sleep is also linked to type 2 diabetes, depression, and even heart disease. Lack of sleep is also known to be one of the biggest risk factors for obesity. Not only has our sleep time gone down, but the quality of sleep is also suffering.

Due to the manner in which our circadian cycle works, exposure to artificial lighting and electronics at night is turning out to be a major contributor to all the sleep problems we go through.

Why is Blue Light Keeping me Awake?

Why is Blue Light Keeping me Awake?

The circadian cycle or rhythm can be defined as being your 24-hour internal body clock that keeps running in the background and fluctuates between sleeping and alertness at regular intervals. Environmental and social cues are known to set the phases of our circadian cycle. Daylight is one of the biggest factors that have an effect on this cycle. In fact, the nature’s clock has three big milestones – sunrise, noon, and sunset. The cycle gets determined from the ganglion cells in the eye’s retinas, which are directly connected to the suprachiasmatic nucleus – the master clock of our body. The circadian clock also has an effect on functions such as brain activity, cell regeneration, as well as appetite.

Since light is such an important factor in establishing the foundation of our circadian cycle, exposure to light thus has a profound impact on our sleep. The human brain tends to ‘wake up’ and become alert when the body is exposed to light. This is why it is harder to sleep in bright light. When the brain is exposed to light at night, the body’s internal biology goes out of sync. This is likely to cause circadian rhythm sleep disorder.

Electronic devices such as mobile phones, laptops, tablets, and other electronic devices, are known to emit a light of blue wavelength. This blue light tricks our brain into thinking that it is daytime, whereas it is actually night and time for us to sleep. Being exposed to a light of a blue wavelength in the evening disturbs the natural sleeping and waking patterns of our brain. This cycle is necessary for the optimal functioning of our body. The body assumes that darkness is the natural cue for the body to go to sleep. However, by staring at a bright screen before bedtime for a prolonged period of time means that we are circumventing this natural process.

Blue light at night time mimics the effect of the sun and this tricks our body into assuming that it should be awake. This causes the body to stop the production of melatonin, the hormone responsible for making us feel sleepy and also regulates our circadian cycle.

What does Science Say?

So does blue light really affect our sleeping pattern? Let us see what studies show.

Study 1: According to Charles Czeisler, Chief of the Division of Sleep and Circadian Disorders at the Brigham and Women’s Hospital located in Boston, there is plenty of evidence firmly establishing that artificial lighting at night has a detrimental effect on many areas of our health. In fact, as per Czeisler, the threat of blue light is actually becoming a growing public health concern and people need to be aware of this problem.

In fact, not just Czeisler, but a large number of researchers, health policymakers, and physicians, all believe that just like a healthy diet and regular exercise is necessary for maintaining good health, similarly sleeping in the dark should become a key aspect of our lives for ensuring good health.

Study 2: In 2016, there was a workshop conducted by the US National Toxicology Program that explored many facets of research which links exposure to blue light at night. The study found that exposure to artificial light not only affects sleep, but it also leads to problems such as weight gain, cancer, heart disease, and depression as well.

Study 3: If this evidence is not enough to change your mind about using your mobile phone at bedtime, then consider this. In October 2016 itself, NASA changed all the lights on the International Space Station to lights that dim and change to a longer wavelength as night falls. Using such lights have shown to have a lesser impact on the human body as compared to blue light.

Study 4: Another study targeting teenagers showed that teenagers are in fact, much more sensitive to light exposure at night. The study showed that even an hour’s exposure to any light emitting device, particularly a phone, is enough to suppress the levels of melatonin by 23%. Two hours of exposure reduced melatonin levels by nearly 40%.

In fact, in June 2016, the American Medical Association also issued a statement sharing their concern that the light emitting diode (LED) lamps are likely to contribute to a higher risk of chronic disease.

Studies are also showing that exposure to blue light at night is making people feel hungrier and reducing the levels of insulin as well, thus increasing the risk of diabetes and obesity. A direct link is now being established between exposure to blue light and weight gain and metabolic diseases as well. A study by research at the University of Haifa in March 2016 showed a direct link between obesity in both men and women with nighttime lighting.

Overall, the health experts agree that the results of all studies conducted on blue light and its relation to your sleep pattern are troubling and warrant action. It can be concluded that exposure to blue light not only affects your sleep, but it affects your entire circadian clock.

What Can You Do?

There are certain steps you can take to reduce the effects of blue light on your sleep. These include:

  • Start using dim red lights as a night light. Red light is least likely to suppress melatonin and affect your circadian cycle. In a dimly light environment, your body starts to naturally produce melatonin.
  • Avoid staring at bright screens at least one hour before going to sleep.
  • If your work schedule is such that you have to use a lot of electronic devices during the night, or if you work in a night shift, then you can consider wearing blue-blocking glasses. There are also apps that filter out the blue or green wavelength of these electronic devices at night.
  • During the day, expose yourself to lots of bright light, particularly natural light so that it boosts your ability to sleep at night and also increase your alertness during the day.
  • You can use smart home solution to allow the lights turn off automatically or gradually at a fixed time.
  • You can try taking carotenoid supplements, which are known to strengthen the eye’s natural ability to block out blue wavelength in the light.


There is a profound impact of blue light on your sleep cycle. That’s not to say that blue light is harmful in all circumstances. You can actually use this short wavelength light when you want to shift your body clock. The blue light will come in handy when you are battling a case of serious jet lag or when you want to be at peak alertness level in the mornings. Shift workers or people who have variable sleep patterns can also schedule exposure to blue light to help realign their circadian cycle. In normal circumstances, though, it is thoroughly advisable that you avoid exposure to blue light towards the evening so that you can get a good night of sleep.

Also Read:


  1. Chellappa, S.L., Steiner, R., Blattner, P., Oelhafen, P., Götz, T. and Cajochen, C., 2011. Non-visual effects of light on melatonin, alertness and cognitive performance: can blue-enriched light keep us alert?. PloS one, 6(1), p.e16429.
  2. Kessel, L., Siganos, G., Jørgensen, T. and Larsen, M., 2011. Sleep disturbances are related to decreased transmission of blue light to the retina caused by lens yellowing. Sleep, 34(9), pp.1215-1219.
  3. Dumont, M. and Beaulieu, C., 2007. Light exposure in the natural environment: relevance to mood and sleep disorders. Sleep medicine, 8(6), pp.557-565.
  4. Mainster, M.A., 2006. Violet and blue light blocking intraocular lenses: photoprotection versus photoreception. British journal of ophthalmology, 90(6), pp.784-792.
  5. Sharkey, K.M., Carskadon, M.A., Figueiro, M.G., Zhu, Y. and Rea, M.S., 2011. Effects of an advanced sleep schedule and morning short wavelength light exposure on circadian phase in young adults with late sleep schedules. Sleep medicine, 12(7), pp.685-692.
  6. Pandi-Perumal, S.R., Trakht, I., Spence, D.W., Srinivasan, V., Dagan, Y. and Cardinali, D.P., 2008. The roles of melatonin and light in the pathophysiology and treatment of circadian rhythm sleep disorders. Nature Reviews Neurology, 4(8), p.436.
  7. Åkerstedt, T., Knutsson, A., Westerholm, P., Theorell, T., Alfredsson, L. and Kecklund, G., 2002. Sleep disturbances, work stress and work hours: a cross-sectional study. Journal of psychosomatic research, 53(3), pp.741-748.
Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:December 2, 2019

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