BLUE LIGHT IS NO FLASH-IN-THE PAN TREND.
And it’s not merely the latest way to push products on patients (though the doubters are out there). Lens products that attenuate transmission of blue light are, at the very least, a way to help patients deal with computer- and device-related digital eye strain and, as we’re starting to find out, perhaps even a way to help stay just a wee bit healthier in the long run.
WHAT WE KNOW
High-energy visible (HEV) blue light—380-500nm—is naturally emitted from the sun. Blue light hitting the retina helps regulate melatonin and, therefore, our sleep/wake cycle and mood. We need a certain amount of exposure to natural blue light to stay healthy. But while some of that range is good for us (~465-495nm), some of it (~415-455nm) can potentially damage the retina, possibly resulting in macular degeneration and other retinal issues, experts say.
Blue light is also unnaturally emitted by digital devices like smart phones, tablets, TVs, and even some lightbulbs. Given our modern society’s propensity for staring at digital screens for hours at a time, seemingly bathed in blue light, ECPs have reason to consider this a potential eye health threat.
Though there has yet to be any direct line drawn from HEV light to macular degeneration, there’s enough known about blue light to cause concern. Many O.D.s feel that providing protection against digital eye strain in the now, and possible retinal damage in the future, is enough reason to prescribe blue light lens products.
“Although overexposure to blue light may have effects on sleep patterns, and research is beginning to indicate an increased risk of retinal damage caused by blue light wavelengths, the immediate concern and the one at the front of most patients’ minds is fatigue and eye strain,” notes Linda Chous, O.D., a pediatric optometrist and owner of Glasses Menagerie in Minneapolis, and the chief vision officer for United Healthcare. “Blue wavelengths are scattered to a greater degree, as opposed to other visible wavelengths, creating increased glare and visual discomfort while using digital devices and LED lighting.”
The science is still evolving on this issue: Long-term exposure to contemporary blue light sources is difficult to replicate in a short-term study. What’s becoming more evident, however, is a line between blue light exposure and circadian rhythm disruption, which can lead to a host of health and cognitive issues. Here’s the latest:
The Need for Lens Products: A recent independent study conducted at Nova Southeastern University College of Optometry was the first study using blue-filtering lenses that crosses over vision and systemic health. It showed that blue-light-filtering lenses (BluTech lenses were used for the study) helped regulate melatonin in the subjects, and subjects had less sleep-cycle disruption than when they weren’t wearing them.
Sleep-cycle disruption is associated with impaired mood and cognitive performance.
The Need for More Study: A roundtable of medical and optical experts in Paris (convened by Essilor) in November 2016 agreed on research indicating that we are being exposed to more blue light indoors than ever before, and it agreed on the need for more clinical research. “While it is generally agreed that there is strong molecular and functional preclinical evidence linking blue-violet light with ocular toxicity, this is yet to be shown in the clinical context,” the roundtable’s report states. Similarly, it noted, clinical data linking blue light and age-related macular degeneration (AMD) is currently limited to epidemiologic studies. It also noted that patients at high risk for AMD would benefit from the use of blue-light-filtering lenses.
“Of course, the science is always evolving, but the data is all pointing toward a mounting body of evidence showing that blue light exposure is a real problem for eye and systemic health,” says Adam Berger, M.D., an ophthalmologist with the Center for Retina and Macular Disease in Florida who regularly reviews blue light science for journals. “I feel very strongly that ECPs should be prescribing blue light products, and not just any products, just the ones that actually work.”
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POINT vs. COUNTERPOINT
When EB surveyed ECPs last year for our Spectacle Lens Virtual Focus Group, more than half (57%) said they believe blue light and blue light lens products to be a topic worthy of the exam room, while a minority believed it to be “mostly marketing hype.” To provide insights on all sides of the debate, we reached out to several respected ECPs and researchers who have both studied and spoken on the topic. Here’s what they told us:
Thomas Gosling, O.D.
Owner of Optical Matters in Littleton, CO
Sunlight is the most powerful source of blue light in our daily lives. In the past, it was the only source. Now we are living among new sources of blue light all day and night.
I agree that the indoor light sources and LED screens are emitting lower levels of blue light, but we don’t know what this long-term exposure over a lifetime will lead to. Why would I not want my AR coatings to have some blue light attenuation?
I’m not saying that viewing backlit LED screens will lead to macular degeneration, by any means. It’s just that in 50-60 years from now, I don’t want to see people showing signs of AMD at earlier times. Why not err on educating our patients, especially our high-risk patients, and offer solutions for the long term?
Jeffrey Anshel, O.D.
Owner, E Street Eyes, Encinitas, CA, and Corporate Vision Consulting
When considering a model to represent the recent concern around high-energy blue light, I found one in Chicken Little. We know that oxidative stress is a byproduct of normal metabolism and the retina has an extreme metabolic rate. Therefore, the retina produces reactive oxygen species (ROS). However, there is little evidence that blue light from computer screens causes most of this damage.
The absorption spectrum of lutein and zeaxanthin match the peak range of blue light. If we want to protect the macula from blue light, the best way to do it is with supplementation of lutein and zeaxanthin, not eyeglasses.
Adam Berger, M.D.
Author and ophthalmologist with the Center for Retina and Macular Disease in Florida
From the perspective of macular health, there are decades of basic science research confirming the harmful effect of blue light on retinal cells. There is also unequivocal clinical data accepted by all retina specialists that proper antioxidant nutrition is essential for reducing the risk for vision loss in patients with macular degeneration. If you accept antioxidants as a protective factor, then you have to accept that blue light is a harmful factor, because it is the blue light that causes the oxidation in the first place.
Peter Shaw, O.D.
Founder and president of Shaw Lens, Inc., adjunct research associate professor, School of Optometry, University of Waterloo, Canada
Currently, some optical suppliers are marketing almost-clear filters with initiation of the spectral reduction at 420nm, and even then, they do not necessarily reduce the energy of said wavelength by 100%. I should add that the blue peak from an LED luminaire is slightly greater than the attenuation of these almost-clear filters at 435nm+/-. Clear or lightly tinted lenses do not have any effect upon wavelengths that are associated with circadian reprogramming.
There are some conditions where short wavelengths are very annoying and possibly damaging. Some disorders, such as diabetic retinopathy, macular edema, and wet AMD, cause the retina to retain fluid. Short wavelengths scatter within these edematous tissues and interfere with vision. They can also cause a delay in the remanufacture of rhodopsin, and vision recovery takes longer with reduced dark adaptation.
BLUE LIGHT PRODUCT GUIDE
A resource for choosing the right blue-light-filtering lens products for your patients.
A proprietary formulation of pigments and dyes embedded in a 1.56 and poly lens for near-clear protection against blue light. Also available in polarized sun. blutechlenses.com
CONANT LENS, INC.
UV++ lenses offer in-monomer HEV filtering in 1.50, Hi-Vex, 1.60, 1.67, and 1.74. Designs include finished single vision, semi-finished single vision, and semi-finished D-28.
CVO partnered with BluTech lenses to create BluTech Eyewear, which combines fashion eyewear with the highest level of blue light protection. Available ready-made in plano and reader lenses and in SV and PALs prescriptions. blutechlenses.com , cvoptical.com
ESSILOR OF AMERICA
Smart Blue Filter: Blue light protection is embedded within Varilux digital, Transitions, and Eyezen+ lenses. essilorusa.com
Eyezen+: A line of four single-vision lenses available only through ECPs, most with an additional accommodative relief for digital eye strain and HEV-filtering properties.
eyezenusa.com , eyezenPRO.com
Crizal Prevencia: A lens treatment that selectively filters blue light. essilorusa.com
Ultimate Lens Package: A bundling of treatments and designs to provide maximum clarity and protection. essilorusa.com
GSRx offers a frame-and-lens combination that provides protection from blue light. Proper Optics Eyewear is available with PrevaBlue, an AR, UV, and blue-light-blocking coating. properoptics.com
Liquet Lens: Blocks 35% of artificial blue light without an amber tint.
Work-Play Lens: Adds contrast and blocks blue light. It can transition from an indoor amber tint to a darker sunglass tint while outdoors for the ideal viewing experience in both worlds. Available March 2018. gunnar.com
HOYA VISION CARE
Recharge is an AR lens treatment that blocks 30% of harmful blue light. Recharge EX3 AR combines exceptional scratch resistance and superior cleanability with blue light filtration. hoyavision.com
TheraBlue is an in-lens filter in 1.67, 1.60, 1.56, and poly materials. Available in SV, PAL, digital round bifocals, and computer lenses, in clear and sun lenses.
SuperResistant Blu is a lens treatment that reduces blue light by about 30% in the HEV light range (380-500nm). seikovision.com
Shamir Blue Light Zero absorbs HEV blue light that falls within the 415-455nm range of the light spectrum. It provides a protective solution for all Shamir Freeform designs. shamirlens.com
KODAK Total Blue Lens is a combination of lens material and AR lens coating that provides 100% direct UV protection and up to 80% filtering of HEV blue light (measured at 380-440nm) while maintaining color vision. Available in progressive, single vision, and computer lens designs with clear and polarized options. kodaklens.us/pro/
BlueShield is a blue-light-blocking lens made specifically for use with Super Optical’s FastGrind all-in-one in-house lens surfacing system. It is a clear lens with 90% overall light transparency. superoptical.com
Alexandra Peng Charton designed computer eyewear specifically to fit non-Caucasian faces. The company partners with a lab to provide blue-light-filtering lenses for the package. tc-charton.com
Transitions Signature VII lenses block at least 20% of the harmful blue light indoors, and more than 85% outdoors. Transitions XTRActive block 34% of harmful blue light indoors and 88-95% outdoors. Transitions Vantage lenses block 34% indoors and more than 85% outdoors. transitionspro.com
Clear Blue Filter: Provides 100% UV protection and filters HEV blue light in a clear, everyday polycarbonate lens. Filtering properties are built into the lens, not in a coating.
Coppertone: Polarized Rx lenses provide 100% UV blockage and two times the solar blue light protection of other green or gray lenses.
VSP OPTICS GROUP
TechShield Blue: Targeted blue light defense in a premium AR coating. techshieldblue.com
SunSync Light-Reactive Lenses: 100% UV protection and targeted blue light filtration from sun and screens in an ultra-fast-reacting photochromic. sunsynclenses.com