Bitey said:
95 is a usable setting I remember fiddling with it a year or so ago, but again your dxlevel should work with and help your hardware, if it is causing more pain than help, then take it as low as you can without breaking the zBlock minimum. I know that 70 and lower makes it so flashbangs do not effect you, at least on the visual side, your ears still ring.
I just tried it at 70 and flashbangs did, in fact, turn my screen white.
95 is the pseudo-dx10 that Steam uses.