Other people have told me that too, that someone might have had a laugh over it. But let's assume that the pan wasn't overcharged and I was sensitive to the hot gases blasting out of the vent and being deflected toward my face. The more powder loaded into the barrel, the more blast that gets deflected.
It's hard for me to understand why some of the experienced flintlock shooters wouldn't usually wear safety glasses with any hot sparks, smoke and micro particles blasting out from the vent and right back into the lock to be deflected.
I'm also aware that the amount of horizontal blast coming out from the side of the vent area is something to be aware & careful about too, especially if other shooters or bystanders are in direct proximity of the vent while on the firing line.
I think that most caplock shooters are aware of the possibility that fragments could fly out from the nipple area and the need for eye protection.
I know that most times people don't get hurt from not wearing any eye protection, but since the possibility exists, it's still a routine practice for most BP shooters whether at the range or while hunting.
I guess re-enactors and competitors aren't encouraged to follow the practice of wearing safety glasses, whether they're of modern, prescription or have antique styling.
Some of the fella's didn't wear any hearing protection at the BP range either though, so I don't know what does or doesn't bother other people.
But since every type of BP gun and loadings present different hazards, I usually err on the side of caution and wear some kind of safety equipment.