Re: I used to do this for a living
They've come a long way in figuring out just what induces nausea, and what doesn't, and avoid that as much as possible.
There was a lot of experimentation I the early days, and they just didn't get it right.
My first ever vr experience was a occulus dev-kit running a banana boat /pirate ship (swinging theme park ride) simulation.
Impressive, but the input from my eyes in no way matched up with the experience the reset of my body was having.
That made me feel sick after a few swings.
Two tables away was another headset. Same model, but the simulation was of an outdoors space you could walk around using a controller.
Much better, but still didn't line up.
Later demos with roomspace, where it's ME moving within the environment instead of the environment moving around me? No nausea at all.
My sister still feels ill using them (her work uses vr too, but for different things) but I suspect there, it's that the headset isn't set up for her properly, IPD etc