Hi,
According to your description, I suppose the issue may be caused by some reasons.
You may experience these symptoms if you have a video configuration on your computer that is incompatible with the Office feature set that is responsible for displaying
the application and for animations in the application.
I recommend you display hardware qraphics acceleration.
Location: File>Options>Advance>Display> display hardware qraphics acceleration.
There is an article mentioned the issue, please refer to following link:
http://support.microsoft.com/kb/2768648/en-us
The article applies in Office 2013, but we can refer to .
On the other hand, I suggest we can update the display drive to check the issue.
Regards,
George Zhao
TechNet Community Support