Hi
Please check this thread: https://answers.ea.com/t5/SimCity-2013/Mac-Mouse-Cursor-and-Display-Resolution-Problems/m-p/7839105#M127554 If your problem matches this issue, click the "Me Too" button on the first post and add your system info & details following the info there. There are a couple of workarounds listed that you can try, while EA works with Apple to hopefully resolve this issue.
If this is not the problem you're having, please start a new thread giving specifics of the issue and your system info.