Can iOS 7 induce motion sickness?
With the new parallax feature, iOS 7 users can have the screen appear as though they are head on, even if the screen is tilted in another direction. The zoom feature works when accessing applications. The zoom feature can not be disabled but the parallax feature can be shut off. Go to the Accessibility menu in iOS 7. Choose "Reduce Motion" and you should be able to eliminate that effect.
For those sensitive to such things, this is no joke. Some have complained about having to go home from work because of severe vertigo. The complaints are similar to what those who used the HTC EVO 3D used to report after viewing the stereoscopic screen for hours.
source: CNET viaTheVerge