Blue Light and Sleep: Tips for Older Adults
Key Takeaways
- Blue light is part of visible light that humans can see. The largest source of blue light is sunlight, but a small amount is also emitted from screens like phones, computers, and TVs.
- It’s not entirely clear how harmful blue light from screens is, but the average US adult reports using digital devices with screens for over 5 hours a day, and lengthened exposure to blue light may increase risks.
- Blue light exposure right before bed can confuse your body’s natural sleep cycle and cause trouble with falling and staying asleep.
- 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.
- 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.
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).Cougnard-Gregoire, Audrey, et. al. Blue Light Exposure: Ocular Hazards and Prevention—A Narrative Review. Ophthalmology and Therapy. Feb. 18, 2023. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9938358.
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 is blue light?
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.How Blue Light Affects Your Eyes, Sleep, and Health. Cultivating Health. UC Davis 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 . 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.” 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
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.
The American Academy of Opthalmology says that screens emit minimal blue light and that this light is no more damaging than the sun. However, blue light exposure can impact sleep and may play a role in some health risks, so there are steps you can take to reduce risks and improve sleep.
Sources of blue light
The largest source of blue light is the sun. Artificial sources of blue light include:
- Fluorescent lighting (LED lights)
- Television screens
- Computer monitors
- Tablet screens
- Smartphone screens
- Smart devices with a screen, like a digital calendar or hub
For 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 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. In one study, American adults self-reporting using digital devices for over 5 hours a day, reflecting extended exposure.
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 limit 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.
- Limit blue light exposure at least 2-3 hours before going to bed, but use blue lighting during the day during activities that require alertness.
- Use night mode when using devices in the evening and at night to reduce blue light.
- Blink more! Studies show we actually blink less when using digital devices, so trying to physically blink more could help reduce the impacts of blue light.
How does blue light affect sleep?
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. Blue light in the evening may be especially disruptive to sleep, so experts recommend avoiding screens 2-3 hours before you want to fall asleep. Exposure to blue light before bed can confuse your body’s natural sleep cycle and cause trouble with falling and staying asleep.
This is because blue light exposure suppresses the secretion of melatonin, a hormone your body produces in response to darkness, which keeps your circadian rhythm, or internal clock, stable.
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. 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. What Are Sleep Deprivation and Deficiency? National Heart Lung and Blood Institute. March 24, 2022. Found on the internet at https://www.nhlbi.nih.gov/health/sleep-deprivation 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. Zhao, Zhi-Chun, et al. Research Progress About the Effect and Prevention of Blue Light On Eyes. International Journal of Ophthalmology. Jan. 1, 2014. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6288536/
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. Kaido, Minako, et al. Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity. PLoS One. April 5, 2016. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4821556/
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. 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/
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. 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]Spalt, Elizabeth W., et al. Time-Location Patterns of a Diverse Population of Older Adults: The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Journal of Exposure Science & Environmental Epidemiology. April 29, 2015. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4641054
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:
- Try to get plenty of natural sunlight during the day, especially early in the morning, to promote a healthy circadian rhythm and prepare for a good night’s sleep.
- 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.The Color of the Light Affects the Circadian Rhythms. The National Institute for Occupational Safety and Health (NIOSH). Centers for Disease Control and Prevention. April 1, 2020. Found on the internet at https://www.cdc.gov/niosh/emres/longhourstraining/color.html
- 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.
- Keep napping to a minimum. Naps that are too long or frequent could interrupt your nighttime sleep.
- 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.
- Check your mattress. A good night’s sleep starts with ensuring your mattress is the best mattress for your body and needs. Not sure what that looks like? Use our guide to the best mattresses of 2024 as a starting point.
- If your partner is keeping you up at night or you have unique needs, like snoring or a painful back, you might also benefit from an adjustable bed that can accommodate a variety of positions.
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
- Cougnard-Gregoire, Audrey, et. al. Blue Light Exposure: Ocular Hazards and Prevention—A Narrative Review. Ophthalmology and Therapy. Feb. 18, 2023. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9938358
- 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
- Prevent Blindness. Your Sight—Digital Devices and Your Eyes. Accessed Aug. 7, 2023. Found on the internet at https://preventblindness.org/blue-light-and-your-eyes/
- 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/
- 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
- Li, Junxin, et al. Sleep in Normal Aging. Sleep Medicine Clinics. Nov. 21, 2017. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5841578/
- Harvard Medical School. Blue Light Has a Dark Side. Harvard Health Publishing. July 7, 2020. Found on the internet at https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
- National Heart Lung and Blood Institute. What Are Sleep Deprivation and Deficiency? March 24, 2022. Found on the internet at https://www.nhlbi.nih.gov/health/sleep-deprivation
- Yanoga, Fatoumata. Does Blue Light From Electronic Devices Damage Our Eyes? The Ohio State University Wexner Medical Center. June 13, 2019. Found on the internet at https://wexnermedical.osu.edu/blog/blue-light-and-vision
- Kaido, Minako, et al. Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity. PloS One. April 5, 2016. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4821556/
- Hazanchuk, Vered. Should You Use Night Mode to Reduce Blue Light? Found on the internet at https://www.aao.org/eye-health/tips-prevention/should-you-use-night-mode-to-reduce-blue-light
- Daneault, Véronique, et al. Aging Reduces the Stimulating Effect of Blue Light on Cognitive Brain Functions. Sleep. Jan. 1, 2014. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3865352/
- Depp, Colin A., et al. Age, Affective Experience, and Television Use. American Journal of Preventive Medicine. March 11, 2013. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3593658/
- Spalt, Elizabeth W., et al. Time-Location Patterns of a Diverse Population of Older Adults: The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Journal of Exposure Science & Environmental Epidemiology. April 29, 2015. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4641054
- Silvani, Marcia Ines, et al. The Influence of Blue Light On Sleep, Performance and Wellbeing in Young Adults: A Systematic Review. Frontiers in Physiology. Aug. 16, 2022. Found on the internet at https://www.frontiersin.org/articles/10.3389/fphys.2022.943108/full
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- The National Institute for Occupational Safety and Health (NIOSH). Centers for Disease Control and Prevention. The Color of the Light Affects the Circadian Rhythms. April 1, 2020. Found on the internet at https://www.cdc.gov/niosh/emres/longhourstraining/color.html