Blue light is very, very bad.

2000k is the same of Sodium High pressure bulb,they was very pleasant for eyes,with golden beam but low cri
There was a thousand on my city streets and now are replace with crappy cool white leds…
what a disgrace

Sorry this is in french : https://www.anses.fr/fr/system/files/AP2014SA0253Ra.pdf

There is a phototoxicity of the blue light for human retina and the part of the blue light that is studied for this toxicity goes from 450 to 470 nm.
The part of the blue light that is studied to affect circadian rhythms goes from 480 to 490 nm.

This phototoxicity is due to a chemical reaction on human eye tissues activated by the blue light (450 to 470 nm).

There are a tons more details about it that I won’t go into because of my broken english.

Which is good because as you may know, the younger you are, the more affected you are. With ages eye’s cystalline lens “deteriorate” and act as a filter that blocks more of the blue light than where you were younger.

Roses are red
Violets are blue
Whichever light is more harmful
I know that life is killing me too

Cree now produces their XP-G3 in a 70 CRI 2200K format. I find that to be particularly interesting as the typical CRI for street lights is 70. 70 CRI at 2200K would be too low for interior usage. Further, I believe the XP-G3 is also an emitter built for and used in street lighting. I have reason to believe that they could be used in something like the RSW series which would be really interesting to see 2200K LED street lights. Color should look superficially similar to SON Deluxe/Super HPS. We are beginning to see the sub-3000K become more and more viable especially after Phoenix’s refit of all 2700K. Those lights look superficially like incandescent light.

Same here, we are in a rented small house in the middle of a nature reserve for a few days, and my home-made lantern with 2000K E21A is my son’s nightlight.

Personally I’m not a great blue peak worrier, but I do welcome the “human centric lighting” shift of the industry, if not for health reasons, it will make lighting so much more pleasant. :slight_smile:

It’s really bad to see public and private places where was nice warm light replaced with low quality Leds

Yes unfortunately. The small house that we rent atm has all led lamps, I did not bring my spectrometer but judged from how the reds are rendered compared to my EDC (95CRI 3000K SST-20) they have CRI’s somewhere in the 80’s. :frowning:

A rought but nice looking modded flashlight with a real sweet tint light !
bravo for le chic* of this lantern djozz !
It would have deserved an annual BLF/OL Contest’s entry.

Good old fashioned lumens :wink:

Thank you Tally-ho :slight_smile: . I failed to make pictures during the mod so the contest was out of reach. I hope for peaceful enough times ahead in my life so that I have the motivation for a nice entry for next year.

Blue light is nothing compared to blue balls—for your eyes only. :wink:

When you get replacement lens for your cataracts, they are UV protected. So no
Worries. For geezers.

http://www.aboutcataractsurgery.com/uv-lens-implants-iol.html

Don’t get your health advice from blog posts.

Some small green LEDs lights can wake me up after falling asleep, so I blocked them from being visible.
So far small red LEDs light have not woken me up from sleep.
This is the experience I have had personally so far.
Not much experience with pure blue light, except for like 1 week with a back-light on my keyboard.

[emphasis added]

See also: The problem with f.lux . (a reminder that the pump for LEDs is blue-white light, which is always present despite software filters like “f.lux” that change the apparent color temperature by mixing in a larger amount of red and yellow light on top of the basic blue-white)

I don’t believe there is anywhere near the necessary clinical and experimental evidence at this point to claim that there is a causal link between exposure to computer-generated light and cancer. While some melatonin suppression has been shown in very controlled experimental conditions in preliminary studies, the effect on sleep across the general population, if any, is not yet known.

It’s not “computer generated” light at issue — you get the same problem without computers.

Computers and phones are mentioned because many of them nowadays use either fluorescent or LED lights, both of which happen to have peak emission in the very narrow range that suppresses melatonin. And yes, LEDs are fluorescent light sources, driven by a blue-white emission moderated by one or more phosphors to shift the color temperature.

The light from, say, a monochrome VT100 green or amber screen would be computer generated light, but wouldn’t affect melatonin production.

https://cancerres.aacrjournals.org/content/66/20/9789.long
“studies have suggested several mechanisms for the known effects of melatonin”

Much like tobacco, it took a long time before mechanisms were figured out to explain the observed correlation with cancer.

Sunlight coming through a windows is hundreds of times more dangerous, not just blue but in the whole spectrum, so if you really are concerned about cancer you should probably lock yourself in a dark room.

But if you look at the article cited in the original post, which is what most of us are commenting on in this thread, you can see it is computer and other human-generated light the thread is about. I think avoiding normal doses of nature-made blue light is possible only with eyeglasses or other lenses made for that purpose and worn when one is outside or near a window - but that comes with obvious drawbacks/costs.

Your comment about it taking a long time to figure out the mechanisms behind the observed correlation of tobacco with cancer is difficult to understand, in light of the fact that tobacco is not comparable to blue light from human sources. There is today no proven correlation between human-generated blue light and cancer at the levels most people are getting every day.

You can look this stuff up. Seriously, the information is available.

The mechanisms are being worked out, e.g. if you read the linked article at https://cancerres.aacrjournals.org/content/66/20/9789.long you saw this:

Harvard study strengthens link between breast cancer risk and light exposure at night
August 18, 2017 1.36pm EDT Updated August 21, 2017 12.16pm EDT

Artificial Light at Night and Cancer: Global Study
Asian Pac J Cancer Prev. 2016; 17(10): 4661–4664.
doi: 10.22034/APJCP.2016.17.10.4661

https://www.cnn.com/2016/06/21/health/led-streetlights-ama/

Melatonin levels increase after sunset and decrease again when daylight (or artificial light in the critical wavelengths) occurs.
Melatonin suppresses cancer, as well as controlling circadian rhythm and sleep.
It’s artificial light in the blue range at night that’s of concern here. Not daylight.

I often find it’s useful to put my opinion into a Google or Scholar search
like this: scholar light night cancer at DuckDuckGo
before posting what I believe; often what I think I know turns out to be old information.

LOL, I follow most of those... I just feel better on the journey. Yoga/meditation was and still is a lifesaver. Had a "hinge moment" just a month ago that made me stop the junk food and sugar. (pain doctor lowered the boom on diet vs. messed up back) More energy. Feel better. All of my joints feel much better, lost 15 lbs.

Just turned 65 so I'm taking the blue light thing seriously but not obsessively. Thanks for the article.

However...

"No one here gets out alive!" (Jim Morrison) I don't worry 'bout that too much.

Yeah, we switch to low- or no-blue light in the evening, about 8PM, and doing that ended our “up til 1AM” insomnia problems.
Reading late into the evening under a cool white compact fluorescent was a big dose of blue light we did not need.
Now we use either amber-filtered CFLs or amber LED floodlights, ceiling bounced — ample evening light;
and Rosco theatrical filter gels in Canary or Goldenrod over the computer screens.

I’ve found the MrBeams amber lights quite useful — bright motion sensors, plenty of light for getting around without tripping over the dog.