January 25, 2016

Let's Be Clear About Blue Light


Let's Be Clear About Blue Light

Editorial by Dan RobertsScreen Shot 2016-01-25 at 12.00.29 PM
The media is becoming saturated with warnings about the so-called “blue light hazard”. Let’s pull it back a bit by being more specific about who should be most concerned.
In 2006, I published a paper titled Artificial Lighting and the Blue Light Hazard. The purpose of the paper was to warn of the risks of full spectrum (aka “daylight”) lamps for people with compromised retinas. In the paper, I presented research showing that “blue light waves may be especially toxic to those who are prone to macular problems due to genetics, nutrition, environment, health habits, and aging.” I went on to say that “fortunately, healthy retinas have a wide array of built-in chemical defenses against UV-blue light damage.
I was specific about who should be concerned about blue light exposure, but perhaps I wasn’t specific enough. There now seems to be a misunderstanding that virtually all people should avoid blue light, with some media sources and advertisers making such statements as “blue light damages the back of the eye, causing conditions like age-related macular degeneration.”
It is true that blue, or near-UV, light (wavelength of about 475 nm) is at the end of the visible spectrum with the highest potential for damaging the human retina. But, as I wrote in 2006, healthy retinas have a wide array of built-in chemical defenses against UV-blue light damage. They are xanthophyll, melanin, superoxide dismutase, catalase, glutathione peroxidase, vitamin E, vitamin C, lutein, and zeaxanthin. The natural yellowing of the eye’s lens over time is also a defense, as are dark irises. As long as these defenses are in place, blue light is sufficiently filtered. If, however, genetics, poor nutrition, pollution, bad health habits, or aging have compromised the retina, that is when caution is important. Electronic monitors do emit a certain amount of blue light. (Even seemingly white screens contain it in order to make the screen appear brighter.) But the worst problem that viewers with healthy eyes might encounter is insomnia or depression resulting from suppression of melatonin, and research on that is still inconclusive.
The bottom line is that everyone should have their eyes examined regularly, especially if they have a family history of visual disorders. If they are found to be at risk of retinal degeneration, they should be advised to avoid blue light sources, wear protective lenses, and consider supplementing their diets with xanthophylls like lutein and zeaxanthin. These nutrients help to maintain the density of the macular pigment, the part of the central retina that filters blue light. The majority of people, however, who are blessed with healthy retinas should feel reasonably safe with electronic monitors or other types of blue light exposure.
I call upon other writers to clarify that blue light is hazardous to only those whose natural defenses are compromised. Everyone else can enjoy the blue, as long as they are diligent about maintaining optimal eye health through good diet, exercise, regular exams, and common sense.

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