It's VR technology. base simulation frame rates equal to or more than the VR HMD's refresh rate are desirable. When base frame rates are less than the HMD refresh rate there's always a risk if VRID to some users. While some may not consider it an issue, others may.
VRID Tip: Close your eyes and immediately stop the VR session. Rest and avoid movement until your brain recalibrates. There have been a few instances where I have had it, albeit rare. Stopping the VR session is the best thing I found to do. And yes, back when DCS had VR barely going it was a real puke-fest with the DK2...gutting it out also helps :joystick: