Backlit displays hurt our eyes because most apps often use full white backgrounds without taking into account the much bigger surface (that is, light) our eyes is exposed to by doing so, which is roughly double compared to say 10 years ago. That can be corrected by choosing darker themes, but good luck convincing most people to do that.
E-Ink technology needs a lot more time to become a viable option for monitors.
In the office most programmers and designers use dark themes, but in fact they are more straining than light themes because your eyes do more work adjusting for seeing little bright things in the dark than for seeing little dark things in the light - I guess in the end it is a matter of taste.
Or just turn the brightness down. The monitor I'm using now has a dedicated button for cycling through brightness settings. I have it on minimum for general use, and I set it to maximum for games/movies.
E-Ink technology needs a lot more time to become a viable option for monitors.