A Cautionary Note on Blue Light
Recently Boots Opticians, a UK retail chain, was fined 40,000 pounds by the UK General Opticians Council for making misleading claims about blue light. According to Vision Monday, “The complaints challenged two claims made by Boots: that the blue light from LED TV’s, smartphones, sunlight and energy-saving light bulbs cause damage to retinal cells over time; that Boots Protect Plus Blue lenses protect against blue light from these sources.”
Does this mean that the claims lens companies are making about Blue Light Hazard and the efficacy of their blue light products is bogus? Not at all. It just means that there is a certain amount of exaggeration going on, most likely from the suppliers’ marketing departments. Let’s have a quick look at some recent studies to see what we know and don’t know about blue light.
It has been known for some time that blue light is toxic to the retina, (though a connection to AMD is still controversial) and standards for blue light exposure have been established by some regulatory bodies. The issue is whether indoor sources of HEV like LED screens can cause this harm. And the answer appears to be no.
According to A UK study compared long-term exposure to energy saving bulbs and LED screens to established exposure limits, and concluded that “under even extreme long-term viewing conditions, none of the assessed sources suggested cause for concern for public health.” One study is hardly definitive, but it’s important to avoid blanket statements that indoor blue light sources can cause harm.
Multiple sources have shown a correlation between digital screen usage and sleep disorders in adolescents. A review and meta-analysis of 20 studies involving over 125,000 children aged 6 to 19 found that “bedtime access to and use of a media device were significantly associated with the following: inadequate sleep quantity, poor sleep quality, and excessive daytime sleepiness.”
A study of almost 10,000 adolescents aged 16-19 conducted in Norway concluded that “extensive use of these devices was significantly and positively associated with SOL (sleep onset latency) and sleep deficiency, with an inverse dose–response relationship between sleep duration and media use.” This study found a correlation, not just with device use at bedtime, but with cumulative exposure over the course of a day. The authors listed “bright light exposure” as one possible cause.
Suppressed melatonin levels may have more serious consequences than morning grumpiness in teenage kids. Some studies have indicated a link to cancer, heart disease, diabetes and obesity.
Digital Eye Strain
Blue light appears to be a significant contributor to Digital Eye Strain. According to Gary Heitling, OD, Senior Editor of allaboutvision.com, “Because short-wavelength, high energy blue light scatters more easily than other visible light, it is not as easily focused. When you're looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused visual "noise" reduces contrast and can contribute to digital eye strain.”
Effectiveness of Blue Light Filters
In addition to alleging that blue light from man-made sources could damage retinal cells, Boots was fined for claiming that their blue-light products could protect the eye against such damage. Logically, if the threat can’t be proved, protection against the threat can’t be proved either. However, blue light blocking AR and blue-filter lens materials clearly have beneficial effects for wearers who use digital devices. According to Adam Gordon, O.D., clinical associate professor at the University of Alabama at Birmingham School of Optometry, “Products created to block out blue light minimize eyestrain when using computers and digital devices, but have not been tested or shown to prevent any type of eye disease.”
While some lens suppliers and ECPs are likely overstating both the extent of the indoor blue-light problem and the effectiveness of the solutions available, there is really no need to. Patients are experiencing discomfort daily from blue-light exposure, both in the form of digital eye strain and sleep issues (and the latter may have longer-term health implications.) Current blue light solutions, like PrevaBlue® and UVhp™ from GSRx, are effective in addressing these problems.
 O’Hagan, M Khazova and LLA Price, Low-energy light bulbs, computers, tablets and the blue light hazard. Eye (2016) 1-4. www.nature.com/eye
 B Carter, P Rees, L Hale et al, Association Between Portable Screen-Based Media Device Access or Use and Sleep Outcomes: A Systematic Review and Meta-analysis. Jama Pediatrics, December 2016 http://jamanetwork.com/journals/jamapediatrics/article-abstract/2571467
 M Hysing, S Pallesen, K Stormark, R Jakobsen, A Lundervold, B Sivertsen, Sleep and use of electronic devices in adolescence: results from a large population-based study. BMJ Journals, January 2015. http://bmjopen.bmj.com/content/5/1/e006748
 Harvard Health Letter, Blue Light Has a Dark Side. http://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
 G Heitling, Blue Light: It’s Both Bad and Good for You. All About Vision. http://www.allaboutvision.com/cvs/blue-light.htm
 A Rohan, Debunking Digital Eyestrain and Blue Light Myths. UAB News, April 25, 2016. https://uab.edu/news/youcanuse/item/7258-debunking-digital-eyestrain-and-blue-light-myths