Editor still captures mouse when not active

I put some OnMouseOver functions in my game and I've noticed that the editor will continue to capture the mouse position when it's in the background and I'm in another program like chrome or photoshop. When I bring Unity to the front again, the game window will be filled with whatever was activated. This makes it difficult to test and research at the same time, requiring a restart or minimizing the window instead of alt-tabbing.

I'm looking for functionality to disable the mouse input when Unity is not the active process.