Are you sure they are playing the right games (standing/sitting in place, teleport-only, modern headset that isn't a Google Cardboard)? I haven't seen or heard

Are you sure they are playing the right games (standing/sitting in place, teleport-only, modern headset that isn't a Google Cardboard)? I haven't seen or heard of anybody getting seriously sick after headset went 90Hz and the 6DOF tracking started getting really solid. Back in Oculus DK1 days that was still a serious problem still (3DOF, 60Hz), but once we got the Rift that pretty much disappeared. The wrong games will of course still make people sick, but so will a roller coaster in the real world. That's a game design issue at that point, not a hardware limitation.