No, we're not talking Pinetop Perkins here. The subject is research on the various effects on living things of nighttime lighting, particularly that which has a significant blue component.
We have been writing about the intimations that modern artificial lighting at night, and the light coming off computer and tablet screens, is not good for humans -- see "Related posts" below. (Most such screens are backlit with white-light LEDs that produce a lot of blue.) But this specialist web community does not have quite the reach of GigaOM, Business Insider, or the Washington Post. More people outside the lighting business are learning about the issues now.
The Post's article centers around the work of RPI's Mariana Figueiro, whom we have met before. Its focus is on the recent finding that blue light from tablet computers suppresses melatonin production much more in teenagers than it does in adults. "Even when exposed to just one-tenth as much light as adults were, the teens actually suppressed more melatonin than the older people," the Post reported. And while one hour of tablet use before bedtime didn't suppress melatonin enough to disturb sleep in adults, two hours did.
The historically unprecedented exposure to blue light at night magnifies the natural pattern in teenagers to be alert later into the night. "Asking a teenager to get up at 7:00 am is like asking me to get up at 4:00 am," the Post quoted a Harvard sleep researcher. Alertness and learning suffer. Some school districts are opting for a later starting time, and are seeing test scores improve as a result.
More than sleep
But lowered levels of melatonin secretion by the pineal gland do more than disturb sleep -- a lot more. GigaOM reporter Elizabeth Armstrong Moore shed some light on the variety of deleterious effects besides lost sleep -- "from diabetes and certain types of cancer to lupus and migraine headaches."
Besides its role in regulating the circadian cycle, melatonin acts as an antioxidant and an anti-inflammatory agent. A search of PubMed turns up studies on melatonin in the treatment or prevention of lupus, MS, and rheumatoid arthritis; diabetes; and migraine headaches.
The eyes have it
Over the last year concerns have been rising among optometrists, who have been seeing high levels of retinal stress in young people, presumably due to the prolonged use of LED-backlit computer screens. The fear is that macular degeneration could get an early start in children exposed to historically unusual levels of blue light. The American Macular Degeneration Foundation agrees.
Surgeons who perform cataract operations are increasingly implanting blue-blocking interocular implants (IOLs), though the practice is not without controversy. And as Business Insider reported, suspicion is growing that blue light can hasten the formation of cataracts in the first place.
What's to be done about all the blue light in our lives? We could try making LEDs with less blue in their spectrum, such as the LSG bulb represented above left. We could use the blue-reducing utility f.lux on all our electronic devices (for Android there is an equivalent app, Twilight). We could wear blue-reducing glasses -- one journalist believes this to be the most effective single step we can take to mitigate the effects of nighttime blue light.
The lighting industry has a significant role to play in educating the public about the effects of light, and in producing products that do not violate the Hippocratic Oath.
— Keith Dawson , Editor-in-Chief, All LED Lighting