motion sickness with certain games

whenever i play certain types of games such as 1st person shooters where the camera moves a lot, i play fine for about 30 minutes, but after that i start to become really dizzy and nauseous. is there anything i can do to prevent it, like taking some medication before or during playing? also are there any non pharmacologic options? like conditioning myself somehow? because taking meds everytime i want to play seems too inconvenient