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From wikipedia: >Production of melatonin by the pineal gland is inhibited by light to the retina and permitted by darkness. Its onset each evening is called th
by Houshalter 12y ago
From wikipedia:
>Production of melatonin by the pineal gland is inhibited by light to the retina and permitted by darkness. Its onset each evening is called the dim-light melatonin onset (DLMO).
It is principally blue light, around 460 to 480 nm, that suppresses melatonin, proportional to the light intensity and length of exposure. Until recent history, humans in temperate climates were exposed to few hours of (blue) daylight in the winter; their fires gave predominantly yellow light. The incandescent light bulb widely used in the twentieth century produced relatively little blue light. Wearing glasses that block blue light in the hours before bedtime may decrease melatonin loss. Kayumov et al. showed that light containing only wavelengths greater than 530 nm does not suppress melatonin in bright-light conditions. Use of blue-blocking goggles the last hours before bedtime has also been advised for people who need to adjust to an earlier bedtime, as melatonin promotes sleepiness.
When used several hours before sleep according to the phase response curve for melatonin in humans, small amounts (0.3 mg) of melatonin shift the circadian clock earlier, thus promoting earlier sleep onset and morning awakening.
https://en.wikipedia.org/wiki/Melatonin#Light_dependence https://en.wikipedia.org/wiki/Melatonin#Light_dependence
- rthomas6 12y agoSo how can I know whether or not a light produces some blue light? Alternatively, do you have any recommendations for blue-blocking goggles?
- ctdonath 12y agoProbably a matter of "light temperature". Low temperatures of 2500-2700 K (aka "warm white") are reddish, while high temperatures around 3000 K (aka "daylight" [ETA: in advertising parlance]) are bluish. Go to a well-stocked hardware store and they may have a display demonstrating the differences.
- weddpros 12y ago3000K is still considered very warm white. Daylight is 5700k. http://en.wikipedia.org/wiki/Color_temperature http://en.wikipedia.org/wiki/Color_temperature
- nitrogen 12y agoAll white lights produce "some" blue light. As the other comment mentioned, the white point/color temperature indicates how much. I'm a fan of lights with adjustable color temperature, such as the Philips Hue bulbs. I use ~5000K-6500K when working, then fade down to dimmer light at ~2500K in the evenings. I use a Kinect for this, rather than the Hue app.
- iLoch 12y agoI have Gunnars that I wear at home. The advantage is you're not limited in use when compared to flux. You can get them in prescription as well, however they're already fairly expensive.
- herf 12y agoGunnars do a great job at blocking UV and some kinds of glare, but they mostly don't block the light around 480nm, so they can't block all alerting light. You want glasses that look orange (not pale yellow), like the $7 Uvex ones.
- rom16384 12y agoOrange Cocoons work, http://www.cocoonseyewear.com/sunwear/product.php?id=190 http://www.cocoonseyewear.com/sunwear/product.php?id=190
- herf 12y agoInstall dimmers! And use warm-dimming bulbs like incandescent/halogen (or some newer LEDs). The combination of lower brightness and a light that actually dims to 2000K will measurably wipe out the stimulus. Most other kinds of lighting will not.
- sanoli 12y agoIf you just want to give it a try, the ones made by Uvex are pretty cheap and of good quality: http://www.amazon.com/Uvex-S1933X-Eyewear-SCT-Orange-Anti-Fog/dp/B000USRG90/ref=sr_1_2?ie=UTF8&qid=1406648843&sr=8-2&keywords=orange+goggles http://www.amazon.com/Uvex-S1933X-Eyewear-SCT-Orange-Anti-Fo...
- istvanp 12y agoSo this might explain why I started sleeping better when I installed f.lux[1] which starts eliminating blue light from your screen as soon as the sun sets. [1] https://justgetflux.com/ https://justgetflux.com/
- toomuchtodo 12y agoFlux user here. Its fantastic. Please try it!
- philsnow 12y agodebian/ubuntu users can `apt-get install redshift`. you can add it to your ~/.xsession if you're a luddite like me, or find some other way to make sure it's always running when X is running.
- joezydeco 12y agoIs there a market for a mobile screen protector film that blocks the 460-480 nm spectra? How do you sell people on that science?
- imjk 12y agoLook at above comment about f.lux. You don't even need hardware; you can do it with software. But a quick search for such filters already delivers a lot of results: http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=blue+light+screen&rh=i%3Aaps%2Ck%3Ablue+light+screen http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3D.... Just choosing one of those results randomly (http://www.amazon.com/Green-Onions-Supply-Anti-Fingerprint-Protector/dp/B00FERNIY4/ref=sr_1_fkmr1_2?ie=UTF8&qid=1406646075&sr=8-2-fkmr1&keywords=blue+light+screen+460-480+nm+spectra http://www.amazon.com/Green-Onions-Supply-Anti-Fingerprint-P...) seems to address that light spectrum specifically: "They reduce blue light from your screen by 38% over the most harmful portions of the visible light spectrum (380 to 500 nm)"
- joezydeco 12y agoThere are a lot of people that can't/won't jailbreak their devices to install f.lux on them. That's the market I'm thinking about. But thanks for the links on the existing screen films. Didn't know this was a thing already.
- herf 12y agoThe cheapest option is to wear orange glasses like the $7 Uvex S1933X. Room light is a big stimulus (especially if you don't have dimmers), and they're a lot easier to use than screen films. We measured the spectral response here: https://twitter.com/JustGetFlux/status/398599984334909440 https://twitter.com/JustGetFlux/status/398599984334909440
- cheepin 12y agoYes. See http://humbledmba.com/become-a-morning-person-how-to-end-insomnia-f http://humbledmba.com/become-a-morning-person-how-to-end-ins...