Cougarfalcon83 This sounds familiar. I get burning, red eyes from my AMOLED phone when it's in PWM mode, meaning it is flickering at 240 Hz. Above a certain brightness value PWM turns off. Maybe on iPhone X devices this is possible, too. Most Samsung AMOLEDs are known to flicker even at full brightness.
But that's only half of the story. The software (apps) and OS (ROM) can contribute to eye strain, too, as described in detail inside the "Usable Smartphones" thread.
hpst This caught my attention. Does anyone know why this would be? Those utilities aren't reducing bluelight frequencies getting to your eyes really, just tinting things, so even if you were hypersensitive to blue light it shouldn't make such a difference.
I have an idea about this: Pixel 2 is AMOLED. That technology has no backlight but many small red, blue, and green LEDs as subpixels. So when you turn down blue, what happens is that the blue LEDs go down in brightness, resulting in less blue light.
There are apps that can display only 1 color in fullscreen (I use "Bad Pixels" from F-Droid for this). When I set it to pure blue and then put on my $10 blue-light-blocking glasses, the display, although emitting a bright blue, appears as if it was turned off.
However, judging by what I have read over time, even backlit devices should reduce blue light successfully by, as you said, tinting the colors with their TFT matrix. The small difference is that a minor amount of white backlight light, including blue, still leaves the panel in between the subpixels - this is why black screens still glow a little.
To reveal the true spectrum you can look at the light with a cheap spectrometer. It will tell you how the colors are distributed, and roughly how much blue light there really is. When you use it to look at a white AMOLED screen, you only see 3 stripes of blue, green, and red. The rest of the spectrum is completely missing.
@f3likx must be lucky that his hardware/software setup apparently doesn't introduce eye strain when tinting the screen. I can't use the night mode on my device without making it unusable.