I'm not an expert but I thought a large part of motion sickness comes from the fact that you perceive motion visually but there is no confirmation from the inne

I'm not an expert but I thought a large part of motion sickness comes from the fact that you perceive motion visually but there is no confirmation from the inner ear (as in real life these two sensory inputs work together to maintain your balance). The other way it's also true (sea sickness), where the inner ear registers motion (the ship bobbing due to waves), but you don't see that you are moving (doubly so if you are inside) so again there's conflicting sensory input. I don't suffer from seasickness normally, but a few years back we had a knotted up anchor chain so I went in to service the winch and there was a bit of a swell outside. In about 30 minutes I was quite ill. Once I fixed the winch and went out it all dissipated quickly when I could see the sea & horizon moving again.