[parkher]

Yes, I am aware of that argument, as far as I am concerted it is a marketing propaganda.
In fact we have a glowing screen and it shines directly into the eyes, it makes no difference what was the initial direction of the light.
Besides, the light really is not directed toward the e-ink screen. It spreads parallel to the screen, but the top is clear, so the whole screen glows in effect. It still glows into my eyes, as opposed to a reading light behind and above my head shining towards the reader.
Even with a clip-on light, the lighted area expands beyond the screen, so you are right, the frame is illuminated. But that reduces the unhealthy contrast between dark and light.

In any case, when we looked at the e-ink screen with the internal illumination, and then with a clip-on light, the difference was like night and day. With the clip-on light, the screen looked so much more like real paper, so much friendlier to the eyes. With the internal lighting - so much more like a lcd screen. You need to see both to experience the difference. Try it. But with a decent clip-on light. Clip-on lights are not all made equal, the evenness and width of the light spread is different and also the hue/warmth of the light.

And I especially hate that trick of Kindle Paperwhite to always use the internal lighting to make the screen look whiter, and without letting the buyers know it, at that.

With the newer crop of the internal lighting, where you can change the warmth of the light, at least you can make the screen look like a brownish paper of a cheap paperback, and therefore more natural than bluish-greenish something not quite paper. So that makes the emergency use more pleasurable, I guess. I give you that.