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Given we already know it disrupts melatonin (as well as noctural wildlife), this feels like one of those cases where the burden of proof is on the proponents, b

by st26 8y ago

Given we already know it disrupts melatonin (as well as noctural wildlife), this feels like one of those cases where the burden of proof is on the proponents, before we roll out millions or billions of dollars of LED streetlights around the country. You know who really stands to benefit the most? The companies that get to sell us blue equipment, and then next sell us replacement blue-filtered equipment when we prove night time blue light is a problem. The cities that have already installed 5000K or 6500K (aka "daylight") lamps will be the natural experiments.

docker_up 8y ago
You're kind of proving OP's point. You're just spouting off "facts" with no real understanding behind what exactly was said. What exactly did the study say? We've seen more than enough examples on HN about studies whose premise and conclusion have been mistranslated so many times, who's to say this isn't another case of it?
- st26 8y ago
  What exactly did the study say? Exposure to blue light suppresses melatonin levels. Melatonin is previously understood to regulate sleep. Ergo, while causation between blue light exposure and sleep quality is not proven, we at least have grounds for suspicion. What understanding am I missing? What "facts" are being misused?
  - nkurz 8y ago
    What understanding am I missing? What "facts" are being misused? Jumping in from the sidelines, when you say "Exposure to blue light suppresses melatonin levels", I think the main thing missing is a notion of "dose response". How much blue light causes how much change in melatonin, and how does this affect sleep compared to other factors? Others here in the thread are suggesting that a blue LED indicators on electronics are a travesty. While I hate LED's of any color in my bedroom at night, and tape over indicator lights of all colors, I'm doubtful that this level of exposure affects melatonin levels. Does you think it does? Looking into it now, this seems like a good overview : https://medium.com/swlh/is-blue-light-destroying-your-sleep-no-but-worrying-about-it-is-b0ab1290bfee https://medium.com/swlh/is-blue-light-destroying-your-sleep-... And this is a good look at how melatonin supplements actually work: https://slatestarcodex.com/2018/07/10/melatonin-much-more-than-you-wanted-to-know/ https://slatestarcodex.com/2018/07/10/melatonin-much-more-th... An interesting point from both of them is that in controlled studies, both melatonin supplements and blue light exposure seem to cause about a 10 minute difference in time to fall asleep. While real, this is a much smaller effect than I would have guessed from most of the popular press coverage.
  - docker_up 8y ago
    Did you even read the study? Or just the highlights on USA today? How much did it suppress melatonin levels? You don't know any of this.
adrianN 8y ago
We could still roll out billions of dollars of LED light but conservatively choose LEDs with a warm spectrum. Yellow LEDs exist.
- bamboozled 8y ago
  Same thoughts exactly, I have a LED lamp which allows me to adjust the color, all the way down to a dark red (insanely warm) glow, in which it’s hard to red certain printed texts. Not sure when LED became blue light only? Helps me sleep incredibly well and it’s an LED.
  - mark-r 8y ago
    LEDs put out a lot of blue because most of them are based on phosphorescence, and high energy light (blue or ultraviolet) is required to drive the phosphors. It's possible to make a white LED without phosphors by combining different colored LEDs, but they're not as bright and much more expensive. That's also how you make them color adjustable.
- st26 8y ago
  Yes, this is my preferred approach. Although, care must be taken, as many nominally warm LED's still have a huge amount of blue emissions. For example every Philips colored LED bulb, including red and orange, have a big spike of blue. The only exception is the yellow bulb, which is sold as a bug bulb... In other words, the engineers only chose to control the blue emissions in the one bulb; everything else is default full of blue.

by st26 8y ago

docker_up 8y ago

You're kind of proving OP's point. You're just spouting off "facts" with no real understanding behind what exactly was said. What exactly did the study say? We've seen more than enough examples on HN about studies whose premise and conclusion have been mistranslated so many times, who's to say this isn't another case of it?

st26 8y ago
What exactly did the study say? Exposure to blue light suppresses melatonin levels. Melatonin is previously understood to regulate sleep. Ergo, while causation between blue light exposure and sleep quality is not proven, we at least have grounds for suspicion. What understanding am I missing? What "facts" are being misused?
- nkurz 8y ago
  What understanding am I missing? What "facts" are being misused? Jumping in from the sidelines, when you say "Exposure to blue light suppresses melatonin levels", I think the main thing missing is a notion of "dose response". How much blue light causes how much change in melatonin, and how does this affect sleep compared to other factors? Others here in the thread are suggesting that a blue LED indicators on electronics are a travesty. While I hate LED's of any color in my bedroom at night, and tape over indicator lights of all colors, I'm doubtful that this level of exposure affects melatonin levels. Does you think it does? Looking into it now, this seems like a good overview : https://medium.com/swlh/is-blue-light-destroying-your-sleep-no-but-worrying-about-it-is-b0ab1290bfee https://medium.com/swlh/is-blue-light-destroying-your-sleep-... And this is a good look at how melatonin supplements actually work: https://slatestarcodex.com/2018/07/10/melatonin-much-more-than-you-wanted-to-know/ https://slatestarcodex.com/2018/07/10/melatonin-much-more-th... An interesting point from both of them is that in controlled studies, both melatonin supplements and blue light exposure seem to cause about a 10 minute difference in time to fall asleep. While real, this is a much smaller effect than I would have guessed from most of the popular press coverage.
- docker_up 8y ago
  Did you even read the study? Or just the highlights on USA today? How much did it suppress melatonin levels? You don't know any of this.

adrianN 8y ago

We could still roll out billions of dollars of LED light but conservatively choose LEDs with a warm spectrum. Yellow LEDs exist.

bamboozled 8y ago
Same thoughts exactly, I have a LED lamp which allows me to adjust the color, all the way down to a dark red (insanely warm) glow, in which it’s hard to red certain printed texts. Not sure when LED became blue light only? Helps me sleep incredibly well and it’s an LED.
- mark-r 8y ago
  LEDs put out a lot of blue because most of them are based on phosphorescence, and high energy light (blue or ultraviolet) is required to drive the phosphors. It's possible to make a white LED without phosphors by combining different colored LEDs, but they're not as bright and much more expensive. That's also how you make them color adjustable.
st26 8y ago
Yes, this is my preferred approach. Although, care must be taken, as many nominally warm LED's still have a huge amount of blue emissions. For example every Philips colored LED bulb, including red and orange, have a big spike of blue. The only exception is the yellow bulb, which is sold as a bug bulb... In other words, the engineers only chose to control the blue emissions in the one bulb; everything else is default full of blue.