I was intrigued, then, when I stumbled on an iPhone feature that’s supposed to prevent, or at least reduce, carsickness. The feature is called Vehicle Motion Cues and it overlays dots on the left and right side of your screen. Those dots move as the vehicle you’re riding does things like turn or speed up. The Vehicle Motion Cues feature, which you can find in System Preferences under Accessibility > Motion, puts circles on both sides of your displays. Consider toggling the feature so that it only turns on while you’re in a moving vehicle and seeing how it feels.