Obviously just an anecdatum. An e-paper reader(Kindle Paperwhite, though I'm planning on getting something non-amazon...) helps me read in bed without any distractions. Since it has a sidelight, I don't need a lamp, which keeps light pollution at a minimum. The device is basically useless for anything other than reading, so there's no push notifications or messenger chats popping up. I regularly pass out after 3-4 pages.

In addition to that, the experience for reading while travelling is far superior simply due to the battery life.

E-readers to me are a good example of the Unix philosophy applied to hardware. Do one thing, and do them well.

Though in my own case, I have no use for a powerful tablet computer. Reading is literally my only use for the form factors. For someone who does need a "real" tablet, a separate e-reader might not be worth the investment.

I also didn't find any papers regarding to differences, but I have my eyes and experience.

I feel uncomfortable reading from a high quality OLED (iPhone X) or IPS panel (Apple MacBook Pro displays and an HP EliteDisplay) after reading for an hour or so, but when I open my Kobo Glo HD, I can read for hours without eye strain or feeling uncomfortable, even with front light. It just feels natural and doesn't make my eyes dry, forehead stiff or feeling exhausted. This is a study I'm conducting myself for 5+ years. So, it's enough of a data for me.

That's interesting I switched from a kindle to an iPad mini a few years ago and except for reading outside in the sun, I didn't notice any downsides concerning the display.

I started with a 212 DPI display (PocketBook 626), then moved to Kobo, which is 300 DPI, and the effect was much more dramatic.

If you're not using displays all day long, you might not be straining your eyes much, and may not be feeling it, too. Try using some artificial teardrops (without any additives, preservatives or active ingredients). If you feel relieved after using them, you're simply unaware of being uncomfortable, then.

I also am not aware of any papers that show any benefit, so it's just a personal preference to me.

This may be a bit insane, but E-Ink displays feel less "artificial" to me, more "rooted in the real world", even if the content is exactly the same.

E-Ink with lightly amber front lighting is super cozy, IMO. I tried using IPS displays with a similar, very warm colour temperature - it just looks wrong and I get a headache.

I thought it may be caused by the "E-Ink = reading, LCD/IPS = Work" connection, but the cozy feeling is also there when using E-Ink as a terminal.

It's strange, IDK :D

I think it's very common for people to use "wrong" settings on their monitors (besides often bad ergonomics in general). If you have pretty much any amount of natural ambient light in your office, and you don't adjust the monitor's brightness over the course of the day, it's probably wrong for long durations. Many folks seem to leave monitors at default settings, which are generally way too bright for most environments. A simple test would be holding a piece of paper up to the screen - white on the screen shouldn't be brighter than the paper.

A monitor that auto-adjusts not just brightness, but contrast and color temp, based on input from a couple cameras (both in front and behind the display) has the potential to be incredible.

Samsung's "The Frame" televisions get close to this, as do some smarthome hubs and smart picture frames, but I've never seen an equivalent standalone desktop monitor with these features.

There is some academic work in this area. If you're searching, use the terms "electrophoretic", "EPD", or "epaper" rather than "eink". Most focuses on either readability or subjective evaluation rather than eyestrain though. There's also a lot of related work on optimal contrast/luminance ratios independent of display type. Generally I think the reason people subjectively prefer eink is because the research tends to find that (for users that do not require visual accessibility accomodations) readability decreases after the luminance contrast ratio exceeds about 10 (e.g., Wang and Chen 2000), which puts eink in a natural sweet spot, and the need to increase LCD backlight brightness in well-lit rooms (e.g., Miyao et al. 2016).

That's just a single data point, but here's my experience. I have severe myopia, and I experience discomfort when reading from a screen over a prolonged period of time. I read a lot, and I can't read for more than two hours even on a quality LCD screen. With e-paper, three hours of continuous reading are not an issue. If my reading habits were as simple as reading for an hour before bedtime, I don't think I would need anything more than a tablet.

Here's my anecdata:

Reading fiction on a 300+dpi OLED set to white on black is absolutely wonderful for me, and I can do it for several hours in a row, provided that the ambient illumination is not full sunlight.

Reading fiction on a 180ish dpi E-ink screen is fine but a little aggravating because changing to the next page takes so long. Not-very-black on light grey is not my favorite color scheme.

Try a relatively modern 300 dpi screen like a paperwhite or Kobo Glo HD, and you'll be really amazed how comfortable reading becomes.

Does it improve either of the things I actually complained about?

Yes. New generation of displays have greater contrast ratio and way faster page change speed. 300 dpi e-ink displays at least one generation newer than 212 dpi screens I've used before and they visibly improve speed, contrast and readability.

The screen (Kobo Glo HD) I'm using is probably one generation behind of current screens. It's on par with paperwhite 2 or 3 IIRC.

I can just zone-out and read for hours without noticing any lag, distracting refreshes (my Kobo does full/reversing refresh every 5 or so changes), and I prefer to any screen I've experienced until now, which were not low end, low-dpi screens of any kind.

Moreover, I'm very rarely buying paper books now. If I can find the title electronically, I just purchase it from the Kobo store.