Heh, my eyes are neither young nor old; they're thirty
Still, I've given them a hard time between CRTs, LCDs, print, and large doses of unadulterated sunshine. I'll get eyestrain trying to read long texts from the big glossy LCD on my desktop, but with the matte display on the Wind I just adjust brightness until my eyes are comfortable and set a good contrast in FBReader (right now I'm using black-on-yellow, and I can read comfortably in a dark room with brightness at minimum). In anything short of direct sunlight, it's less strain than an old paperback in indirect light. Maybe that will change a fortnight of years from now, but for the time being it's the best Swiss-army-knife gadget ever.
I do think LCDs and eInk will evolve to the point where a single device can provide the benefits of both. Who knows, though, maybe netbooks and smartphones will end up being "gateway" readers, introducing people to the medium and serving as a stepping stone to an eInk device down the road.