Blue Light and Sleep Through the Lens of Older Adulthood

Aug 29, 2023

Fact Checked

Blue light can help you stay alert during the day, but it can affect your ability to fall asleep—and stay asleep—at night.

Written by: Miranda M. Riva, Esq

Medical Reviewer: Chester Wu, MD

Reviewed by: Donya Currie, MA, Senior Editor, NCOA

Key Takeaways

Blue light exposure right before bed can confuse your body’s natural sleep cycle and cause trouble with falling and staying asleep by stimulating your mind and suppressing melatonin secretion, which can influence circadian rhythms.
Disrupted sleep patterns and poor sleep quality are linked to a number of chronic health conditions, including heart disease, kidney disease, high blood pressure, diabetes, stroke, and obesity.
Exposure to blue-light-emitting technology like televisions or computer monitors can cause digital eye strain, which might trigger headaches, watery eyes, and blurred vision.

Blue light has become a popular topic of study in recent years, specifically for its effect on the brain and on sleeping patterns. These studies are especially important for the future of eye and brain health considering we spend roughly 90% of our daily lives indoors, surrounded by technologies that emit large amounts of blue light (LED lighting, televisions, and computers). ^[1]

To help you better understand what blue light is and how it can affect your health, our Reviews Team gathered the most recent studies on the topic and assembled a tip sheet for how to control exposure to blue light and improve your sleep quality.

What you need to know about blue light and sleep

Blue light has one of the shortest wavelengths and highest energies in the visible light spectrum and makes up about one-third of all visible light. ^[2] ^[3] The visible light spectrum is made up of seven colors—red, orange, yellow, green, blue, indigo, and violet—each with a different wavelength and energy frequency, meaning they have different effects on your eye. For context, research shows “a wavelength between 300 and 400 nm [nanometers] can penetrate the cornea and be absorbed by the iris or the pupil. High energy short wave blue light between 415 and 455 nm is the most harmful.” ^[4]

While the biggest source of natural blue light is the sun, there are several artificial sources as well, like fluorescent lighting and screen-based technology. For example, televisions, computer monitors, smartphones, and tablets are common sources of blue light. Not only can excessive exposure to blue light cause damage to your eyes, it can also interrupt your ability to fall asleep and stay asleep.

The body’s natural sleep cycle is based on lightness and darkness. In nature, the light from the sun signals to the body that it’s time to be awake, while the darkness of nighttime tells the body it’s time to sleep. Exposure to blue light before bed can confuse your body’s natural sleep cycle and cause trouble with falling and staying asleep. ^[5] This is because blue light exposure suppresses the secretion of melatonin, a hormone your body produces in response to darkness and which keeps your circadian rhythm, or internal clock, stable. ^[6]

Why is blue light a bigger concern for older adults?

The potentially negative effects of blue light are concerning for all people, but there are a few reasons why blue light might be a bigger concern for older adults. These include blue light’s impact on sleep cycles, possible impact on eye health, and increased exposure to blue light as we age.

Sleep deprivation negatively impacts older adults more

For many older adults, aging decreases the ability to fall asleep at night, maintain sleep, and get into a deep sleep. ^[7] Disrupted sleep patterns and poor sleep quality is linked to a number of chronic health conditions, including heart disease, kidney disease, high blood pressure, diabetes, stroke, and obesity. ^[8] Decreased amounts of quality sleep can also contribute to mental health problems like depression, anxiety, and dementia. Since older adults are already more susceptible to poor sleep, other contributors—like blue light exposure—should be limited as much as possible.

Effects of blue light on eye health

While the effects of long-term exposure to blue light are still being researched and studied, some studies have shown that blue light can accelerate the occurrence and development of age-related macular degeneration (AMD) in patients who had previously had cataract surgery. ^[4]

Studies on animals have suggested that blue light can cause irreversible damage to the retina’s photosensitive cells, which could potentially contribute to AMD. Additionally, excessive amounts of blue light may contribute to dry eyes and irritation, which can worsen symptoms of other eye conditions. ^[9] ^[10]

If exposure to blue light is from technology like televisions or computer monitors, you may also be experiencing digital eye strain, which can trigger headaches, watery eyes, and blurred vision. ^[11]

We get exposed to a lot of blue light as we age

Excessive blue light exposure is most commonly associated with technology use among younger members of the population, who are frequently on smartphones, tablets, or sitting in front of computers.

But there are two major factors that indicate older adults get more, not less, blue light exposure compared to younger people: First, older adults tend to watch more TV than younger people. Researchers have found that adults age 65 and older spend three times more of their waking time watching TV than young adults. ^[12] ^[13] Secondly, older adults spend significantly more time at home compared to younger people and are exposed to more of the artificial light-emitting diode (LED) lighting that gives off stimulating blue light. ^[14]

Controlling light exposure for better sleep

It’s nearly impossible to rid yourself of blue light exposure entirely, and you may not want to since blue light can be good for some things. “Blue light exposure can be helpful during the day, as blue light can promote wakefulness. But blue light has a dark side,” said Saya Nagori, MD, a board certified ophthalmologist based in College Park, Maryland, and CEO of EyeFacts. “[Blue light] is a natural melatonin suppressant, which again, works well during the day, but can pose a problem for sleep at night.”

Blue light can also increase mental stimulation, cognitive performance, and alertness, which can be beneficial for daytime activities that require focus. ^[15] But too much blue light can trick your brain into staying alert for too long, potentially getting in the way of restful sleep.

“The stimulation that blue light wavelengths bring to your eyes will naturally keep your eyes and brain awake for longer periods of time. When you’re getting ready for bed, you may find that your eyes and brain don’t feel as tired as they should,” Nagori said.

High quality sleep is essential for maintaining mental and physical health. According to Lynelle Schneeberg, PsyD, a Yale Medicine sleep psychologist, “Getting great sleep boils down to two central requirements: having a consistent sleep schedule, and turning off your ‘busy brain.’” ^[16]

One of the best ways to turn off your busy brain is to surround yourself with darkness and engage in a relaxing activity, such as reading from a book or listening to soft music or other soothing sounds.

Sources of blue light

The largest source of blue light is the sun. Artificial sources include: ^[17]

Fluorescent lighting (LED lights)
Television screens
Computer monitors
Tablet screens
Smartphone screens

For older adults who spend a lot of time at home, one of the largest sources of blue light is overhead LED lighting. While this can be great to have on during the day to keep you awake and alert, if you use this type of lighting until it’s time to sleep, you may find it harder to relax so you can fall asleep.

The second largest source of blue light for older adults is the television screen. Whether it’s latent exposure, like having the TV on in the background, or direct exposure, like watching a show or movie, blue light can still penetrate your eyes. Other screen-based technology devices, like tablets, smartphones, and computers, emit blue light as well and can cause eye strain and headaches when used for long, uninterrupted periods.

Controlling blue light exposure at home

Now that we’ve covered what blue light is, how you’re exposed to it, and how it can affect you, it’s time to discuss how to limit and control exposure.

Nagori said while there’s no confirmed evidence on the long-term effects of using blue light filters, she recommends turning on blue light blockers on your digital screens or wearing blue light glasses to filter the light before it reaches your eyes. Blue light filtering is available for both prescription and non-prescription eyeglasses. ”These methods can help reduce the impact blue light has on your internal melatonin,” said Nagori.

See our tips below for more information on how to control blue light exposure at home.

Tips for controlling blue light:

Wear sunglasses when in direct sunlight to protect your eyes from ultraviolet (UV) and blue light.
Use curtains to filter out natural light.
Use blue-light-blocking glasses and blue-light-blocking screens on devices.
Install dimmers for overhead lighting or replace fluorescent lights with blue-light-free bulbs.
Reduce how much time you spend watching TV and using blue-light-emitting devices (tablets, smartphones, and computers).
Choose lighting that is warm in tone to decrease the amount of blue light you’re being exposed to.
Follow the “20-20-20 rule.” For every 20 minutes you spend looking at a digital screen, look at something that’s 20 feet away for 20 seconds to reduce eye strain. ^[12]
Limit blue light exposure at night before going to bed, but use blue lighting during the day during activities that require alertness.

Better sleep in older adulthood

Getting sufficient high quality and restorative sleep is one of the most important self-care opportunities for older adults. See the tips below for more information on how to get better sleep in older adulthood.

Tips for getting better sleep in older adulthood:

Consider using red light for night lights and general lighting at night. Red lighting has no stimulating effect on circadian rhythm and is less likely to suppress melatonin production. ^[18]
Set a bedtime to help you get your optimal sleep.
Have a relaxing bedtime routine, like using aromatherapy, taking a warm bath or shower, or using sound therapy.
Limit sugar, caffeine, alcohol, and nicotine intake before bed.
Engage in physical activity during the day to help your body relax at night, but be mindful that stimulating physical activity close to bedtime can cause the opposite effect and make it harder to fall asleep.
If you don’t fall asleep within 20 minutes of going to bed and you’re feeling restless, try getting out of bed and engaging in a low-stimulation activity rather than just lying in bed. Reading, journal writing, and working on puzzles are some good ways to help reduce sleep anxiety.
Power down blue-light-emitting devices and overhead lights at least 2–3 hours before bed.

Bottom line

While we still need more evidence about the effects of long-term exposure to blue light on eye health, studies show that blue light exposure can impact your circadian rhythm (your body’s internal clock). Exposure right before bed can confuse your body’s natural sleep cycle and cause trouble with falling asleep and staying asleep. Ultimately, poor sleep quality and disrupted sleep patterns can contribute to a number of chronic physical and mental health problems like heart disease, diabetes, obesity, and depression.

To get optimal sleep, limit exposure to blue-light-emitting devices like televisions, cellphones, and computers before bedtime, and practice the 20-20-20 rule: For every 20 minutes spent looking at a screen, look at something else 20 feet away for 20 seconds.

Have questions about this review? Email us at reviewsteam@ncoa.org.

Sources

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NASA. Tour of the Electromagnetic Spectrum. Aug. 10, 2016. Found on the internet at https://science.nasa.gov/ems/09_visiblelight
UC Davis Health. How Blue Light Affects Your Eyes, Sleep, and Health. Cultivating Health. Aug. 3, 2022. Found on the internet at https://health.ucdavis.edu/blog/cultivating-health/blue-light-effects-on-your-eyes-sleep-and-health/2022/08
Zhao, Zhi-Chun, et. al. Research Progress About the Effect and Prevention of Blue Light On Eyes. International Journal of Ophthalmology. Dec. 18, 2018. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6288536
Centers for Disease Control and Prevention. Effects of Light on Circadian Rhythms. April 13, 2023. Found on the internet at https://www.cdc.gov/niosh/emres/longhourstraining/light.html
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Kaur, Kirandeep, et al. Digital Eye Strain—A Comprehensive Review. Ophthalmology and Therapy. July 9, 2022. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9434525/
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Miranda Riva is a writer and licensed Tennessee attorney who has written and edited legal content covering the topics of family law, business law, criminal law, environmental law, and estate law.

Dr. Chester Wu is board certified in Psychiatry and Sleep Medicine, training at Baylor College of Medicine and Stanford University School of Medicine, respectively. He has since established his own private practice in Houston, TX where he provides psychiatric and sleep medicine services.

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