Comment by Eufrat

There is always going to be some movement. It’s impossible for there not to be. Whether it is rendered in the VR environment or happening in real-life through small little motions, there’s a lot of little things that help to establish the mismatch.

It’s probably most like getting car sick. You are obviously moving, but you are also stationary at the same time. This doesn’t happen to folks suffering from motion sickness when they are driving, though, because there is now a physical action tying the motion to your inputs.

This may lead you to ask why people watching a movie in a theater don’t get motion sick and the reason is the same, multiple inputs tell you otherwise. You can see the edges of the screen, you can see the audience, there’s a lot of input telling your body there’s nothing weird going on here. The more immersive, the more some people’s bodies do not handle the illusion well.