90% of the time motion sickness caused by video games is due to the FOV being wrong. Hopefully the game has a FOV setting. In which case, you only have to find the FOV that is appropriate based upon the size of your screen and the distance you are viewing it from. Larger FOV will be better. Unfortunately, a lot of games(especially console ports) don't allow you to change the games FOV internally. There is, this case, still a few things you can do.
Sit back further from your display screen. This increases the amount of stable space in your field of vision. It also allows your brain to cope with the narrow FOV that is locked into most console games display range.
The nausea is caused by your brain experiencing a FOV that doesn't make any sense to it. If you are sitting 4 feet from a 40" display and are locked into some console games 60 degree FOV it will cause this problem. Sitting further back will decrease the visible viewing angle and let your brain see the image how it expects to see it.
A lot of games developers don't seem to care much about this particularly important aspect of design. A locked lower viewing angle makes the game much easier to optimize since less is being drawn on the screen. This is usually very apparent in PC ports since people sit closer to their screens and our displays are growing steadily in size as well. People aren't sitting in front of 15" monitors anymore.