Every time I switched glasses, my old, over the top safety glasses wouldn't fit, so I had to buy new. My favorite out of all of them, was the UVEX brand. (multiple different styles).
My regular glasses are metal (titanium) framed, and with the same material lenses (polycarbonite), that they make safety lenses for (without the rating/testing). I do have accessory side shields and feel these are fine for somethings (using a drill and what not). But my mother works as a surgical nurse for my opthomologist. I've seen pictures of what can happen, EVEN WITH safety glasses (double shot nail from nail gun, first punctured glasses, second penetrated through the eye). What po's me about this, is two things:
1. You shouldn't be telling your kids about spooning out someones eyeball, when you server brussell sprouts. (she did that when we were kids)
2. What makes you complain about lack of, when you don't sell them?
I went to Sam's after my last glasses change and bought true (rated) prescription safety glasses. These will NOT replace a face shield, for grinding, etc. type work (worked as a mechanic for a while), but I don't worry about screwing up my regular glasses. I also know that even they are not impenetrable. (had things knock glasses off my face before as well)
Long term, prescription ones, seem to me to be the best value.