Dwight, I think you've missed the concept of E-ink, this screen could be lit by fire it wouldn't cause less strain for your eyes, I know that wasn't really the subject of your comment but you seemed to hint that.
That being said I get your other concern that a white E-book might reflect more light and have the same effect as backlight and cause eyestrain, and I can't answer this as I have the Amazon Kindle DX Graphite(black) and haven't tried any of these white E-books, but my guess is it isn't that bad as it shouldn't be smooth.

I have a comment on the colour of the case - why is it white?

Just think about it: if one is to go outdoors and try to read in bright sunshine the white case would reflect more light, causing eye strain when viewing black text on an un-lit screen...