Like Ken says, it depends.
Some premium defensive ammunition produces less flash than the more economical loads. .357 magnum is going to produce more flash both because there's more powder, and the blend burns more intensely.
Blinding? Probably not. Harder to see after? Yes. Especially in total darkness. It's probably on par with momentarily touching off a Surefire or another high intensity light and having the light reflect off a white wall back at you. The darker and less ambient light in the environment, the harder it will be to manage the extremes between light and darkeness.
It's just another good excuse to have a good, high intensity light on your person to help manage such a situation.
I've played around a fair bit in darkened indoor ranges. The effects can be managed. It's certainly not blinding, though.
Noise? I've touched rounds off indoors without hearing protection. It hurts, but I could hear. My ears rang, and they were in pain. I winced at loud sounds for a day or two after, but I certainly wasn't deaf.
Go find an indoor range and try it out for yourself. Low light shooting, that is. There's no need to damage your hearing just to prove touching a round off indoors won't make you deaf.