Do e-readers cause eye strain?

There's an interesting blog post over at the NYTimes discussing whether e-readers create eye strain. It turns out that it's not so clear what's the best display for our eyes.

E-paper (such as E Ink) is great - especially outdoors. But in darker situations, an LCD (or any 'lit' display) will actually be better because the e-paper is not emitting any light. I personally think you shouldn't read in the dark anyway - the best solution is to light up the room...

They claim that in some situations, a normal paper isn't perfect either, and can provide an inferior reading experience than a digital display. Personally that's hard to accept - I find it very hard to enjoy reading in an LCD display.