I am fifty something and have had corrective lenses for about a decade. I have always had excellent eyesite, but the usual aging process caught up. You know "my arms don't seem to be long enough to hold a book at the right distance" syndrome. I have read books on an iPod, Kindle (1), Kindle DX, and now the iPad in many lighting conditions. I suffer from Migrains and occasionally I get occular migrains, which you are aware means I see "electrical like patterns" moving across my eyesight. When this occurs I have to take a break from reading and allow my vision to clear. It was very alarming the first time this occured, and is the reason I now wear reading glasses. I can say for me that the Kindle's reflective lighting solution is much easier for me to read for long periods with. I do a lot of technical reading as a Software Engineer. I can spend several hours focused on reading. The backlit displays are much harder on my eyes and require frequent rest periods to allow my eyes to relax. I almost never suffer the occular migrains while reading with a Kindle. It occurs quite frequently with the iPad unless I rest my eyes regularly. For those of the younger set claiming that people are trying to invent a new syndrome, you couldn't be more wrong. As the saying goes, you will understand once you get older. In the meantime you can just assume you know better Learn to take care of your eyes now, you will appreciate it when you still have good eyesite later.