I find myself using cut off wheels and metal grinding discs on my angle grinder a lot, and have not been using any protection other than safety glasses (sometimes). I think it is time to put on my big boy pants, and dig out my face shield.
I have also been trying to figure out how to put an old drill chuck on a handle to use when working with bolts and other smalls on my grinder. Seems it would be safer than what I do now...Vise grips.