Is Blue Light Bad for My Eyes?

Is Blue Light Bad for My Eyes?

by Brian Chou, OD, FAAO, FSLS

  • June 1, 2020

Confused whether blue light is bad for your eyes?  You are not alone.  There is an ample misinformation about blue light, perpetrated by companies selling products that supposedly protect your eyes from it.

Blue light has existed since the dawn of time.  So why all the newfound attention?  In the early 2010s, eye care products started popping up that absorbed or reflected blue light.  The over-arching narrative is that blue light harms the eyes.  The mantra goes that blue light leads to a litany of eye problems, particularly for digital devices users.  But like so many things, this is not the full story.  Here are three things to know about blue light.

#1. Blue Light is Not Proven to Cause Eye Disease

Ultraviolet light is well established to increase the risk of growths on the eyelid and eye surface, sun burn to the eye (solar keratitis), and cortical cataracts.  But the role of blue light and eye disease is murkier.  In the visible light spectrum, blue light carries the highest amount of energy and is closest to the ultraviolet light wavelengths.  In lab studies, blue light can damage cultured retinal cells.  However, real life studies have not demonstrated this.  There is also no definitive evidence that blue light causes or exacerbates age-related macular degeneration, though some researchers have suggested this.  In the United Kingdom, one optical retailer has been fined for making false claims about blue light protection.  That said, it won’t hurt to protect your eyes against blue light, especially if you are at risk for retinal eye disease.  Doing so may bring you greater psychological comfort than actual protection, however.

The greatest source of blue light emissions is not your digital devices.  The sun emits at least 100 times the intensity of blue light.  If you are concerned about light protection for your eyes, prioritize sun protection over concern over digital devices, to limit the known danger of ultraviolet light and the potential danger of blue light.

#2. Blue Light Does Not Cause Eye Fatigue

Several ophthalmic companies market blue-protecting eyewear to video gamers and computer users, suggesting that their products will relieve eye fatigue.  The science tells a different story.  A 2019 study published in Optometry & Vision Science showed that blue-blocking lenses were no more effective than neutral density filters for relieving eye fatigue.  Furthermore, a study published in 2017 found a lack of quality evidence to support using blue-blocking spectacle lenses to alleviate eye fatigue.

#3. Blue Light Can Alter Sleep Cycles

Blue light “wakes up” your body by stimulating cells in your retina (intrinsically photosensitive retinal ganglion cells or ipRGCs) which signal the pineal gland to reduce melatonin production.  Some individuals are particularly sensitive to blue light keeping them awake, especially when exposed to blue light shortly before trying to sleep.  This is like how some have trouble going to sleep after consuming even a small amount of caffeine.  The sensitivity to blue light in altering circadian rhythm varies according to the individual.  If it impacts you in this way, minimizing blue light exposure before going sleeping can help.  Many digital devices have apps – like Night Shift on the iPhone and the Blue Light filter on Samsung smartphones.  These apps make the screen color an orange tone, reducing the amount of blue light emissions.

On the other extreme, some individuals do not get enough blue light and it negatively impacts their mood.  In cases of seasonal affective disorder (SAD), prevalent in the Seattle area during winter, sun lamps can help provide the blue-turquoise wavelengths needed to “wake up” their bodies.

If you are susceptible to seasonal affective disorder and depression, the indiscriminate blocking of blue light may actually worsen your symptoms.

To find out what you can really do to prevent your eyes from going bad — based your individual comprehensive eye exam —  request your appointment at ReVision Optometry today.

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