Anyone who isn't using flux[0] after 8pm is seriously hurting themselves. Once you use it, you can't go back.
The problem is that we keep our brains active late at night and that's the reason why it is hard to get to sleep.
For me alcohol is the one that messes with my sleep. The lack of deep sleep makes me feel tired the next day(s).
Edit: an article about recent studies: https://time.com/5752454/blue-light-sleep/
I find it much easier to fall asleep when the light is redder. Even for example when reading a book, if there's a lot of bright light in the room I will have a much harder time falling asleep.
I've noticed that if I wake up for some reason at night and turn the lights on, if the light is bluer it will tend to wake me up completely, whereas a red light will allow me to stay "sleepy" and fall back asleep quicker.
You are correct, however, that's a confounding problem. The (relatively) weak effectiveness of software solutions is due to blocking only a small percentage of blue light from a (relatively) strong light source (assumes short distance to screen, low ambient light at night).
Blue light (and even some green light frequencies) is a hardwired stimulus feeding into your circadian rhythm. Blocking all blue and green frequencies, e.g. with simple welding glasses, is effective in supporting the creation of melatonin.
But again, having enough melatonin in your system is a necessary but not sufficient condition to be able to sleep.
I still read a lot on computer in the evening, but I get sleepy much earlier.
Flux was great but for the most part modern OS' have caught up and it's no longer needed.
— https://twitter.com/JustGetFlux/status/1288979404677292032
Right up until other people do all the R&D for them so they can pick out the parts they like for a big announcement on stage. It's a smart strategy. They get to look like geniuses while others do the hard work and take all the risk.
I think it doesn't really eliminate the possibility, though, with different numbers.
I use flux, but I also cut all blue light after 10pm. I use 1850k lights (aka candlelight) throughout the house after 10pm. My phone is also yellow shifted and I watch tv yellow shifted too (by only watching from a computer with flux at night).
All those things together made a huge difference in sleep quality.
"Yes. Mainly when I practice good sleeping habits, though."
/s :)
I think it's probably much more of an issue for people already susceptible to inspect insomnia or other sleep issues.
F.lux, Windows 10 night light and Android's bedtime mode are great distractions at best and to me they serve more as a bedtime reminder. I feel that most sleep assistants and other life-hacking tools are mostly placebo that give you the feeling you're in control, which is a state the human brain likes. Sadly, it also means that once you know the placebo effect, those tools become useless. :-)
All this makes my body ready for sleep and at 10 pm I feel relieved to close my eyes and dozing off. I have accepted that I seem to need more sleep than others. Usually after 8 to 9 hours of sleep I wake up on my own.
I did and I went back.
It does very little you use night mode everywhere.
It might help with white backgrounds but I remove or avoid those even during daylight. I do use the 'Eye saver' mode on my smartphone, but only to visually let me know that it's after midnight.
Yes or good old fashioned curtains or window blinds.
But there's this too - and increasingly more stories like it:
https://www.sciencedaily.com/releases/2019/12/191216173654.h...
I'm currently using Iris Pro in max brightness, in which the display doesn't need to flicker, the software still can dim the screen itself.