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BLOG: Become your community's blue light expert
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In my last post I discussed that awareness of blue light is growing among our patients.
Mainstream media stories are taking on the subject of blue light and its health consequences head on. I have seen stories in the lay press regarding blue light and age-related macular degeneration, blue light and visual performance and, just recently, a piece on blue light and sleep disturbance. On April 9, ABC News’ Good Morning America ran a piece on wearing “orange-tinted glasses” before bed when looking at electronic devices. While overall the piece was well done, there was something that was unsettling to me.
The story centered on a recently published study in the Journal of Adolescent Health. In the study, 13 15- to 17-year-old healthy boys were followed for a 2-week period. The authors wanted to investigate whether wearing blue light-blocking glasses, particularly lenses that block blue light within the circadian action spectra (460 nm to 480 nm), would have an effect on sleep-initiating mechanisms.
Subjects were exposed to LED screens while either wearing clear lenses or blue-blocking lenses. Measures of melatonin secretion, vigilant attention/sleepiness and sleep were measured. Results showed significantly more melatonin secreted for the blue light-blocking lenses group along with feeling significantly sleepier at bedtime. Sleep quality between the two groups was not statistically different, although the authors acknowledge that the 1-week trial may not have been long enough to alter circadian rhythm.
An important point I picked up on in reading this study is that the authors found that blue-blocking lenses only modified vigilant attention and subjective sleepiness in the evening before sleep but not the morning after. In other words, when the investigators had subjects wear blue-blocking lenses the next morning vs. wearing clear lenses, there was no measured difference in sleepiness or alertness. I find this striking because, as of late, I have seen promulgated that wearing blue-filtering lenses throughout the day will cause sleepiness and decreased alertness.
Our optometric journals contain articles and advertisements stating that not all blue light is bad. Agreed, we obviously need some blue light to suppress melatonin upon waking. However it is well established that cumulative lifetime exposure to blue light has an impact on retinal cell damage that can lead to AMD. Photo-oxidative retinal damage occurs between 400 nm and 500 nm, the blue light hazard, with shorter wavelengths causing the greatest harm. However, what is not understood is at what duration of exposure and at what intensity will even the upper portion of the blue light hazard cause retinal damage, if at all. Until this is known, I will educate my patients to protect themselves through the use of blue-filtering lenses that offer protection along the entire blue light spectrum.
So, what didn’t I like about the Good Morning America story? Optometry was never mentioned! As the primary eye care profession, we should own the blue light story. Yet this piece interviewed opticians regarding blue-blocking lenses. While opticians certainly have an important supportive role to play in protecting patients from the dangers of blue light, should they be the ones discussing blue light exposure, melatonin suppression and circadian function in a national news story?
The end of the piece features Richard Besser, MD, ABC’s chief health and medical editor (and a pediatrician), who did a good job in explaining the relationship between blue light and melatonin secretion, offering a few helpful tips. But with all due respect, shouldn’t this information be coming from an optometrist or an ophthalmologist, someone with a visual science background? As optometrists we have access to the education and the tools to lead the conversation on blue light; in fact it may well become a cornerstone of the movement towards the much-discussed/less-implemented “medical model.”
At the conclusion of my last post I implored you, my colleagues, to become the blue light experts in your communities. After seeing this Good Morning America story, I cannot understate the importance of my request.
References:
Van der Lely S, et al. J Adolesc Health. 2015;56:113-119.
Algvere PV, et al. Acta Ophthalmol Scand. 2006;84(1):4-15.