You probably figured it out by now, but yes you can-simply do this:
1. Find your FPSCreator Folders. Files-->Gamecore-->Huds-->eyehud.dds
2. Rename eyehud.dds to eyehud_original.dds
3. Make the new blurred vision image you wish to be displayed when the Player takes a bullet.
4. Save the new blurred vision image in the Files-->Gamecore-->Huds folder as eyehud.png
5. Now it should work. If not, then at least you still have the eyehud_original.dds, which you can rename to eyehud.dds, thus it will be back to normal.
Hope this helps,
Tom