[header] How to prevent motion sickness [title] Look out the window frequently. [step] Look at a stable object, such as the horizon. The visual cues of movement will enable your brain to synchronize the visual and physical cues of the swaying vehicle. 
[substeps] If you are in a car, focusing on an object that is too close for you to clearly see, like trees by the side of the road, may make you feel worse. If you can't see the horizon (you are on a winding road, etc.