Short version: Do extended passages of italics give readers headaches? Long version: An idea that struck me yesterday calls for the main character to constantly daydream. He toggles back and forth between the real world and the one he's made up for himself in his mind. I'm probably going to end up writing the story in past tense (Unsure about POV), and the daydreams seem to want to be present tense. However, I'm not sure that's enough to differentiate them from the "real world" sections. Another thought of mine was to use a line break and put the daydreams in italics. But I've heard that long passages of italics are turn-offs to readers and publishers. Will the italic passages--anywhere from a paragraph to a page or two in length--throw readers off?
It won't throw readers off, but I think there is no need for italics. When you first introduce the character, make it clear that he tends to daydream. Then, just start the daydream without using italics. The reader should understand that this is where the daydream begins from the drastic change in what the character is experiencing. You could also gives clues to where the daydream begins by describing the transition from the real world to the daydream world. The past tense and present tense thing won't make sense. Stick with one or the other.
They may. Personally, I don't like to read them when they are too long just because it tends to get annoying. I usually skim through them if they are unnecessarily long. An idea- you could seperate them into chapters- daydream and real world. And just have a ton of short chapters (in which italics won't be necessary for the day dream chapters.) As for the tenses you use... I think you just need to be consistent. Choose one for the story and one for the daydreams.
They don't give me headaches if they belong there. But I'm in the minority because just about everybody else says italics give them headaches. *shrug* In your example, I really wouldn't use italics (and I'm a heavy italics user). I'd just separate the daydreams into scenes with scene breaks, especially if they're long. If it were just a paragraph here and there I would understand and tolerate italics, but pages of daydreams? If the daydreams are so important to go into such detail, they shouldn't be relegated to italics; they deserve their own space as individual scenes. Maybe only the first and last sentence of the daydream sequence could be italicized, to indicate that it's a daydream? I wander off into the sunlit field. How did I get here? *insert long daydream sequence* I decide that my time here is done. I turn and wander back up the road and away from the field. Something like that?
they'd annoy me, as well as give me a headache, should i ever read them, which i most likely wouldn't... as noted above, there's no real need for using them... if you're changing the tense to present and providing an adequate segue from the regular narrative, why resort to fancy fontwork?
Long passages in italics don't bother me one bit... this I wander off into the sunlit field. How did I get here? *insert long daydream sequence* I decide that my time here is done. I turn and wander back up the road and away from the field. ...does, though (sorry, tehuti88,) because I expect the first sentence to be a thought. Tense changes would definitely throw me off.