I’m currently humming to “Blue” by Eiffel 65, but the lyrics connote a different meaning than they did 15 years ago.  The topic of blue light has gained significant interest in recent years due to our almost unavoidable use of LED-based TV’s, smart phones, tablets, and computers.  News outlets often release melodramatic headlines cautioning the use of electronic screens with its damaging effects on the eye.  Truth be told, blue light from your devices will not make you blind. Whew, right?!

With that being said, there are several animal studies that have shown signs of retinal toxicity when eyes are exposed to light of high intensity in the blue part of the visible spectrum (400-490nm).  However, many of these experiments utilized light levels far beyond natural conditions with unrealistic models (ie. albino rats with dilated pupils with continuous exposure for days to months).  Given the way we normally use our devices, which emit substantially lower energy levels, this exposure is unlikely to induce direct tissue damage.

So why do my eyes hurt staring at the screen (my thoughts right now)?  While spending long hours staring at the screen will not permanently harm your eyes, it can cause discomfort that may last throughout the day.  We call this Computer Vision Syndrome or Digital Eye Strain.  These symptoms can manifest in dry eyes, eye fatigue, blurred vision, tearing, and/or headaches.  Viewing a digital screen often makes our eyes and body work harder.  Poor lighting, uncorrected vision problems, screen glare, and poor back and neck postures exacerbate this.

At rest (think relaxing on the beach), our eyes have a blink rate of about 15 times per minute, or once every 4 seconds.  When looking at our screens, the blink rate can decrease by half.  With each blink, our eyes take a mini “nap” from external stimulation, and our eyelids function like windshield wipers to spread the tear film and remove debris.  Personally, I’m a little obsessive about cleaning my car windshield.

To reduce eye dryness and fatigue, remember to blink often and supplement your tears with over-the-counter lubricant eye drops when needed.  Use the 20-20-20 rule: every 20 minutes, look away from the screen at something 20 feet away for at least 20 seconds.  Add a couple of long hard blinks before returning to scrolling through that sweater sale.

Should I buy those blue light blocking glasses?  A very common question I get.  And my answer: it’s probably not necessary.  A systematic review of the literature by Lawrenson and colleagues in 2017 found a lack of high quality clinical evidence to support using blue light blocking spectacles to improve visual performance, alleviate fatigue or conserve macular health.  The symptoms we experience from prolonged screen time are more linked to how we use our devices, not the blue light emitted by them.  I advise my patients to first try dimming their screen brightness and/or turning on “night mode” to reduce glare and lessen eye discomfort. Some find a matte screen protector helpful.  It is also important to wear the appropriate corrective lenses for a screen-viewing distance; for some, this may mean a separate pair of computer and/or reading glasses.  Lastly, since blue light may alter circadian rhythm, it is good practice to limit screen time a few hours before bed.

If you’ve made it this far, I want to emphasize an important point: the largest source of low-wavelength radiation, including blue light still comes from the sun.  Sunlight contains both blue light and UV light, the latter of which is a known risk factor for age-related macular degeneration, carcinoma, cataracts, and retinal pigment epithelium damage.  When outdoors, make sure to protect your eyes (and the skin around them) with a good pair of UV-A (320-400nm) and UV-B (290-320nm) blocking sunglasses.

To preserve your vision for as long as you can, think of your eyes like any other organ.  Taking care of your overall well-being is also the key to good eye health.  Don’t forget to see your local Optometrist annually to facilitate early detection of disease and to keep you seeing your best!

References

American Optometric Association. “Computer Vision Syndrome.” American Optometric Association, www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y. Accessed 16 July 2021.

“Blue-Light Hype or Much Ado about Nothing?” American Optometric Association, 11 July 2019, www.aoa.org/news/clinical-eye-care/health-and-wellness/blue-light-hype-or-much-ado-about-nothing?sso=y. Accessed 17 July 2021.

Krigel, A., et al. “Light-Induced Retinal Damage Using Different Light Sources, Protocols and Rat Strains Reveals LED Phototoxicity.” Neuroscience, vol. 339, Dec. 2016, pp. 296–307, 10.1016/j.neuroscience.2016.10.015.

Lawrenson, John G, et al. “The Effect of Blue-Light Blocking Spectacle Lenses on Visual Performance, Macular Health and the Sleep-Wake Cycle: A Systematic Review of the Literature.” Ophthalmic and Physiological Optics, vol. 37, no. 6, 17 Oct. 2017, pp. 644–654, 10.1111/opo.12406.

Porter, Daniel. “Blue Light and Digital Eye Strain.” American Academy of Ophthalmology, 10 Dec. 2020, www.aao.org/eye-health/tips-prevention/blue-light-digital-eye-strain. Accessed 17 July 2021.

Rosenfield, Mark. “Living with Blue Light Exposure.” Review of Optometry, 15 Sept. 2019, www.reviewofoptometry.com/article/living-with-blue-light-exposure. Accessed 16 July 2021.

Tosini, Gianluca, et al. “Effects of Blue Light on the Circadian System and Eye Physiology.” Molecular Vision, vol. 22, 24 Jan. 2016, pp. 61–72.

Vicente-Tejedor, Javier, et al. “Removal of the Blue Component of Light Significantly Decreases Retinal Damage after High Intensity Exposure.” PLOS ONE, vol. 13, no. 3, 15 Mar. 2018, p. e0194218, 10.1371/journal.pone.0194218.

If you have a wellness themed topic you would like to share or learn more about, and/or blog/vlog about as an expert in a health/wellness related field, please reach out to shelby@cclyme.org. 

Shelby Wood
Manager of Program Development
CommunityCare of Lyme
Shelby@cclyme.org
802-468-7776