I've been using IOS 7 on my iPhone 5 for the past few hours. And I agree, these animations are making me nauseous and have motion sickness.
I've turned off parallax, but the biggest thing that giving me a headache is the constant zooming in and out when you open and close apps.
I think there's many people in the same boat like me who cannot watch 3D films or play FPS video games like Halo, cause after 10 minutes, I feel like throwing up. And the feeling doesn't away easily. And I don't get used to it, even over time...
I really hope Apple puts out a fix to disable these animations for the many users who experience problems with motion sickness.
Otherwise, I may have to sell this phone, no joke. I've had the last 4 generations of iPhones, but this is that big of a problem for me...