I already use f.lux (even during the day), and I dont keep my screen too bright or too dark. I even bought a second pair of glasses with a weaker prescription, and try to remember to look away every 20 minutes (which is annoying when focusing)

I started a project that I focus on after work, so Im in front of screen for 10-14 hours a day now. I wont mind spending $1,xxx on a e-ink monitor if the feedback is generally good. I have a kindle and it's noticeably more comfortable to look at.

I'm also curious of the psychological effects of working from an e-ink display, since it's a very different medium.