Is blue light filter a gimmick?

[Jason38]

To this day I still don't use LED bulbs in my house and have all Incandescent bulbs and a few halogens. I have 6 plasma TV's in my house mostly 2013 Samsung TV's and I have 5 CRT TV's. Plasma and CRT I still find to be the best screens for motion blur and low blue light. I do own 2 XG270 240HZ gaming monitors and find them both incredible. For my eye comfort I had to go into the full control setting and make the red 100, green, 80 and blue at 50 and I turned the contrast down a bit more so I could turn the brightness up more. At those settings the harsh white back grounds that come from LED screens doesn't bother me.

I would love to get OLED computer monitors but it's not really a thing yet but I'm OK with that as the 2 View Sonic monitors I have are amazing. I do have a Samsung S20 phone which is OLED and 120HZ. OLED is another screen I have always performed with well and it must be cause of the fast GTG and true blacks. I do have to turn the brightness down probably a little more than most people would be used to but I have to do that for all screens. My eyes are incredibly sensitive to bright lights.

[alberto91]

My Blur Busters / TestUFO is already mentioned/credited/coauthor in more than 20+ peer reviewed research papers.

It's definitely not a gimmick, but sometimes certain benefits are exaggerated because some manufacturers implement it very poorly. Also, there are contamination by ambient environment (cheap LED bulbs that emit a lot of blue peaks, even for warm white LED bulbs, due to the LEDs they use)

There are multiple independent behaviours from blue light that are unrelated to each other:
- Mood effects or sleep effects (orange light is more relaxing than blue light)
- Short-term effects on eyes (some people eyes temporarily go blurry when staring at screens all day long)
- Long-term damage to eyes (like ultraviolet light; but blue light can still slowly harden your eye lens, requiring you to begin wearing glasses at age 45 instead of age 55)

The studies often only focus on one or the other.

Even if you don't fall asleep sooner, you may still have a better sleep -- some studies don't necessarily measure quality of sleep.

Long-term damage to eyes from screens is still very real. It's only a multiplier factor (e.g. making you wear glasses sooner or needing LASIK sooner) but it's real, and the problem is more pronounced for brighter high-blue-light screens)

Also, studies is fogged by many effects (like LED streetlamps and daylight LED bulbs) so removing blue screens may do nothing to accelerate your sleep nowadays because of how everything else went LED.

It's also why I prefer warm-white CRI 95 lighting nowadays (I pay extra for my LED bulbs), and anything below CRI 90 is not allowed to gbe screwed into my lightbulb sockets usually. And it is best to drapes closed so I don't see the outdoor blue-colored LED streetlamps. More cities are now switching to the better warmer LED streetlamps especially in residential neighborhoods, but some neighborhoods are bathed in really bright bluish-white light at night, so if you're unlucky, do some mitigations for that.
Definitely not gimmick but definitely exaggerated. Even if you eliminated sleep effects, you still have the other issues.

If I block out all the other blue light sources (lightbulbs, streetlamps, etc) -- when this happens I've eliminated a lot of blue light from other sources at night. Suddenly, one blue screen going to night mode, seems to make a bigger difference. Maybe not in sleep, but in keeping me calm. There's a lot of non-screen noise.

Even if this did not exist, there's still long term damage (blue light as a curing radiation to harden your eyes' lens and making you unable to clearly refocus between close objects and far objects -- you become more permanently nearsighted or permanently farsighted -- and need glasses). That long-term damage is more slow damage than ultraviolet, but still there. It's a work hazard for anyone who has to work with IT, programming AND on screens for a living -- me -- and I'm already getting some minor vision effects at age 47 -- Being farsighted I hold my smartphone at full arm extension now. Probably gonna LASIK my eyes to fix things up a bit. Just a matter of time.

Eventually might need lens-replacement surgery which is paid for by my Canadian health care system, it's a common eye surgery procedure in Canada, when your original eye lens are no longer able to change shape / full of cataracts / etc. In Canada, 1.1 million eyeball modifications are made by surgeons per year (all of them, from LASIK to cataract surgery). The screens do make the surgery happen a few years earlier nowadays.

Also, the LED spectrum of white is not identical. Low-CRI lights have a very sharp blue peak, even for warm LED lightbulbs. Which means all the green-blue light is redirected instead to increasing the amount of blue light and red light while leaving color temperature unchanged. So you've got sharp peaks at blue and red to create the warm white, with a very green-deficient part of the spectrum for low-CRI warm white LEDs. So sometimes the low-blue-light mitigations don't help as much as true fuller-spectrum LEDs with higher CRI that lowers the sharp blue peak of the LED spectrum. If you're buying cheap 50 cent Walmart LED bulbs, you might want to upgrade 'em to lower-blue-light LED light bulbs. One screen doesn't do a hoot of a difference if you have 100 cheap LED bulbs all over your house all simultaneously generating sharp blue peaks despite being warm-color bulbs. Getting these bulbs to CRI 93-95 makes a massive difference with a flatter color spectrum with less blue-light peak.

The low blue light on many cheap-backlight panels are slightly gimmicky in that they don't modify the backlight LEDs themselves but try to block some blue light by making blues darker. But you still have those sharp-ish blue peaks. Less so, but still there compared to some better backlights and others -- a new LED technology is ultraviolet LEDs that use phosphors to generate blue light, for a more fuller spectrum red/green/blue, then an UV filter to completely block the unused UV light -- this eliminates blue peaking completely. Not many lightbulbs use this ultraviolet-phosphor technology, but it's another method of eliminating the blue spectrum peaks.

Now...

This long-term damage from common blue-peaks of fluorescents/LEDs/etc, obviously, is completely unrelated to the sleep-issue part of blue light. But it's still another benefit of proper true low blue light in all aspects of life (office lighting, home lighting, screens you stare at). Whether this is a drop in the ocean, or a major improvement, depends on how blanket your mitigations are to push your need of eyeglasses another decade or so.

Thanks for giving such a detailed answer and clearing my misconceptions.

[Dalek]

I would say that blue light filter isn't a gimmick. I have gotten used to it and whenever it turns off, I feel like a vampire looking at my screen. I feel more stressed instantly. I would say it's definitely worth having it on. You don't notice the orange tint after using it for an hour or so.

[Chief Blur Buster]

I need to add, since I recently got computer reading glasses...

Also, many off-the-shelf and prescription glasses have blue light filtering -- things looks slightly more orange through these glasses, and the bonus -- it works on LCDs.

The glasses I wear now (I'm 48) during computer work have a built-in mild blue light filter which helps with the fact that monitors "low blue light filters" are unable to filter blue-light in LCD greys because you can't lower blue of RGB(0,0,0) without an external physical filter.

Good for long sessions at the command shell, Dark Mode, etc. at night.

[kyube]

Might be useful for someone! A review of some blue-light blocking sunglasses, tested with a spectrometer.

phpBB [video]

EDIT: Also, a very cool discussion I've found in regards to this topic! https://www.reddit.com/r/sleephackers/c ... t_indoors/