[Lucid:]

I don't usually get headaches per se, but my artistically-inclined mind spazzes out when things in the distance are just as sharp as things in the foreground, because they're not supposed to be that way. or worse! when something is being focused on so it's sharp, but something fuzzy flies in from above and is fuzzy for a moment even though it's 3D'd to be closer to you, I freak out. (happened to a bird and a bunch of the floating lanterns in Tangled and I got upset.)