. I was well on the road to my current -11 prescription before the LCD was invented
. In fact, it's slowed down since then, but there might be a small matter of age involved there.
Regarding the idea eyestrain is caused by too much light entering the eye - this is obvious if you've ever been snowblinded, but I wonder whether the intensity differences involved here are significant. Sunlight can be literally a hundred times as intense as light in a well lit office, and totally swamps out a PDA screen, but isn't the ability to read outdoors considered one of e-ink's advantages?