How Blue Light is Ruining Your Sleep

Blue light is omnipresent—it emanates from the sun, electronic devices, and fluorescent and LED lights. While it can be beneficial during the day, too much exposure at night can wreak havoc on your sleep. Blue light interferes with your circadian rhythm by suppressing melatonin, the hormone that signals your brain it’s time to sleep, tricking your body into thinking it’s daytime. Overexposure to blue light not only affects your sleep but also increases your risk of serious health issues like heart disease, cancer, obesity, and diabetes.

The Ubiquity of Blue Light

What is Blue Light?

Blue light is everywhere. Step outside, and you’ll get a healthy dose from the sun. It also comes from LEDs used in energy-efficient bulbs and screens on TVs, computers, tablets, and smartphones. Blue light has a short wavelength, producing more energy than lights with longer wavelengths, like red light.

While blue light can be beneficial—waking you up, making you more alert, and even improving your mood—overexposure, especially at night, can be detrimental. Blue-light emitting goggles and panels are used to treat issues like seasonal affective disorder (SAD), jetlag, and premenstrual syndrome. Hospitals even use blue light to treat jaundice in babies.

The Impact of Blue Light on Sleep

Blue Light and Circadian Rhythm

Newer artificial lights like LEDs and compact fluorescent light (CFL) bulbs lack most of the infrared, violet, and red light found in sunlight, increasing the intensity of blue light to levels we’re not evolved to handle. This “junk light” bombards us throughout the day and night, disrupting our sleep.

Blue light suppresses melatonin, the hormone that tells your brain it’s time to sleep, by stimulating light sensors in the retina called intrinsically photosensitive retinal ganglion cells (ipRGCs). These sensors send light information to the circadian clock, telling it when to sleep and wake up.

A 2014 study found that people who read from light-emitting devices before bed took longer to fall asleep, slept less deeply, and were more alert than those who read printed books. Overexposure to blue light at night has been linked to serious health issues, including:

Cancer: A study found a direct link between blue light exposure and an increased risk of breast and prostate cancer. People exposed to high levels of outdoor blue light at night had a higher risk of developing these cancers.
Diabetes and Weight Gain: A 2016 study found that adults exposed to blue light while eating in the evening had higher glucose levels, slower metabolisms, and more insulin resistance.
Heart Disease: Disrupted sleep from blue light exposure increases the risk of heart disease. Blue light is also linked to obesity and metabolic disorders, significant risk factors for cardiovascular disease.
Vision Loss: Blue light can lead to macular degeneration, damage to the retina that often results in vision loss. More than 11 million people over the age of 60 have some form of macular degeneration.

Protecting Yourself from Blue Light

Practical Tips to Shield Yourself

As a night owl, I’ve learned to take precautions to protect my circadian rhythm while working late. Here are some strategies to shield yourself from blue light overexposure:

Unplug Unnecessary Devices: Go through your bedroom and unplug or tape over LEDs to blackout your sleep area. Carry electrical tape when traveling to cover blue LEDs in hotel rooms.
Invest in Blackout Curtains: A dark room equals better sleep. Use velcro to tape down the sides of the curtains and a valance on top to block light seepage. Foil over windows is another option.
Switch to Amber or Red Bulbs: Replace compact fluorescent lights with amber or red bulbs to reduce blue light exposure.
Wear Blue Light Blocking Glasses: These glasses, usually orange or red-tinted, block harmful wavelengths.
Use Night Shift Mode: On Apple devices, use Night Shift mode to adjust screen colors to warmer tones. For Android devices, set up blue light filters based on your device brand.
Shut Down Devices Before Bed: Aim to turn off electronic devices at least two hours before bed. If that’s not possible, use light filter apps to reduce blue light.
Take Carotenoid Supplements: Macular carotenoids like lutein, zeaxanthin, and astaxanthin protect your eyes from junk light. Supplements like Eye Armor can help reduce oxidative stress caused by blue light.
Increase Exposure to High-Quality Light: Spend time outdoors in the sun daily to balance artificial light exposure. Use LED red bulbs or halogen lamps and consider sitting in an infrared sauna to boost energy and mental performance.