Question might be: How many, who require bifocals, have ‘normal’ strength prescriptions. One simple lens per eye is easy. Combining 2 different prescriptions for each eye is rather hopeful for them being anything like simple.
Please enlighten us on what you consider as ‘not too much money’ (compared to a simple prescription).
I used to have toughened lenses for laboratory work, but prefer over-glasses (cheap to replace when scratched) for where hot metal and abrasive grinding grit might be airborne.
A long time ago, I had plastic safety prescription glasses supplied by my employer. They would soon fall off due to the heat! Hope they are better these days.