As a kid, I was told to turn 90° so that the back and forth of my eyes reading were in line with the motion of the car. This was soooo before any kind of electronic devices. Hell, the radio in the car still had the giant push buttons for saving stations.
the theory being, at constant velocity in a straight line, your body feels at rest, so you want to look somewhere that reinforces that. looking out the side window has scenery rushing past, which is the opposite.
turning sideways and reading sounds like a nightmare.
(I have also been on bumpy flights, no issues whatsoever, even when reading a book at the same time.)
Yes it helps. As in getting you back to "barely normal". (Also you can't do anything around the boat because you're looking at the horizon)
The theory make sense but some people have the thing turned to 11
But I used to get sick playing Quake, so maybe I'm in the 11 group.