Crystals can form in the fluid of the inner ear and cause benign paroxysmal positional vertigo (BPPV). When they stimulate the nerves that give us our sense of balance the room “spins.” While it’s happening our eyes dart (nystagmus) and we experience vertigo. You should always consult a medical professional and not try to doctor yourself or your friends. These movements may not be appropriate for some individuals. That said, here is what I have found in my internet research:
The Epley Maneuver
These three videos demonstrate how to deal with a BPPV instance at home.
The Kanalith Maneuver
A rose by any other name? These videos describe the moves differently but the goal is the same.