How Blocking Blue Light Helps You Sleep

Is blue light exposure blocking you from getting good sleep? If you’re reading this in the evening hours, then the answer is likely yes. Blue light comes from many sources, including the sun—but blue light from phone screens, LED lights, and other electronic sources can inhibit you from drifting to calm, deep sleep. 

Research shows that prolonged exposure to computer screens and devices can damage your cells and DNA—just like the sun. The blue light spectrum and electromagnetic fields (EMFs) from computer screens bombard your cells with different forms of radiation. This can harm your health and speed up the aging process, with serious impacts that include cellular and DNA damage, brain and neurological effects, premature aging, skin hyperpigmentation, and blocking your ability to get a good night’s sleep.  

Your body’s circadian rhythms help you naturally produce melatonin, and determine when you fall and stay asleep. But blue light exposure at night blocks your body’s natural production of melatonin—blocking your ability to relax and reach deep, rejuvenating sleep cycles.^1,2Melatonin is naturally produced by your pineal gland in your brain, which regulates your responses to light and controls your body’s sleep/wake cycles by producing melatonin when it detects darkness.  

Any type of light exposure in the evening can block melatonin production and interfere with sleep. However, blue light is more disruptive to sleep because it has a stronger impact on your body’s melatonin cycles compared to other forms of light.³ 

Even more damaging, blue light from screens also raises stress hormones including cortisol and adrenaline, that not only derail relaxation and sleep, but also increase your sensitivity to stress in general.⁴ 

Cellular and DNA damage, increased stress hormones, and lack of rejuvenating sleep combine to create the perfect storm of damaging factors that can speed up aging, decrease your energy and brain power, and increase your risks of long-term health issues.  

The top solution is to try avoiding blue light exposure at night. But that means no movies, late night scrolling, or evening work. To protect your eyes, you can opt for night-mode on many devices, which changes the light from blue to amber. You can also try special blue light blocking glasses with amber lenses to help filter the blue light and help protect your eyes, as well as your melatonin production.  

Sources:

1. Tosini G, Ferguson I, Tsubota K. Effects of blue light on the circadian system and eye physiology. Mol Vis. 2016 Jan 24;22:61-72. PMID: 26900325; PMCID: PMC4734149. 
2. Mortazavi SAR, Parhoodeh S, Hosseini MA, et al. Blocking Short-Wavelength Component of the Visible Light Emitted by Smartphones' Screens Improves Human Sleep Quality. J Biomed Phys Eng. 2018 Dec 1;8(4):375-380. PMID: 30568927; PMCID: PMC6280115.
3. Blue Light Has a Dark Side. Harvard Health Publishing website. Updated July 7, 2020. Accessed Sept 14, 2021.  
4. Petrowski K, Bührer S, Albus C, Schmalbach B. Increase in cortisol concentration due to standardized bright and blue light exposure on saliva cortisol in the morning following sleep laboratory. Stress. 2021 May;24(3):331-337. doi: 10.1080/10253890.2020.1803265. Epub 2020 Aug 10. PMID: 32723201.