Thanks, George. Obsidian fragments are one of the sharpest natural objects. When I lived near RPI (engineering university in Troy,NY) the someone on the biomedical engineering staff there sold obsidian scalpel blades to cosmetic surgeons because they made the most delicate cuts then known. They use lasers for that now, I think.
I wear safety goggles when handloading, testing out a new gun, or knapping. Wonder if our ancestors used snow goggles or a mask or just left their vision up to the gods....
