I took my prescription to the optical department at Sam's Club for prescription safety glasses. Safety lenses, frames and side shields for no-line bifocals were about $150 three years ago. Don't know current prices. Do NOT just put plastic lenses in your old frames--those are not safety glasses. Lenses and frames are impact resistant in safety glasses. If you are a turner, I would also wear a face shield.
"Individual commitment to a group effort--that is what makes a team work, a company work, a society work, a civilization work."