Or you could just have simple english... LCD uses transmitted light, eInk uses reflected light and that seems to be easier on the eyes for many people (including me)...
I say seems to save this thread degenerating into the usual LCD vs eInk battles from those who have no trouble with LCD to those who hate them as a tool of the devil... and it's all anecdotal anyway... personally I'm in the eInk camp for general reading and that's a good enough anecdote for me - I don't give a damn for those who disagree, they don't have my eyes or my migraines so