The abstract says, "Results suggested that reading on the two display types is very similar in terms of both subjective and objective measures."
The section quoted by SteveEisenberg suggests that there was a subjective difference that they discounted.
I don't know how they could objectively measure my problem. The LCD screen doesn't make my vision blurry. It doesn't make my eyes stiff. I can still read with alacrity.
The LCD screen causes me pain. The longer that I read, the longer the pain lasts afterward.