Virtual reality sickness

Simulator sickness is an effect in virtual reality that occurs due to conflicts of the visual system and the vestibular system.

It can include headaches, dizziness, and nausea.

VR sickness is largely caused by micro-differences between the human brain's vestibular state and the perceived or expected visual state. This can be caused by the weight of the headset causing a visual delay when turning the head due to the headset being heavy.