Damage not flashing?

Hey, I'm having a problem with my damage flashing and it's extremely irksome. My screen used to flash whenever I took damage, like it's supposed to. But suddenly it stopped working. I checked the options screen, and the damage flash is selected. I tried with it deselected as well, but it's still not working. I reboot the game and try, and it stays the same. It's been like this for a while, and it's incredibly annoying because whenever I get close to dying now, it won't flash dangerously red to warn me. I end up dying more frequently now because the screen won't flash. Please help?

Is your "Postprocessing" option off? It disables all damage flashing when it's turned off to help optimize your graphics. It's under the Video tab in the in game options menu.