You completely ignored human error aspect. Before the blood donation centers used one time use equipment, donors were getting infected with something nasty every now and then. You can sure as hell expect people to commonly forget to properly sanitize those syringes.

There is also the reality that a sealed package is more of a guarantee of sterility than something that should be autoclaved. Even in the US there have been cases of nasties being passed by inadequate cleaning.

And we had a big scandal locally. Were they doing a shoddy job of colonoscopies? Probably. But genetics left no doubt that they were using one needle per jab, but one syringe per patient. And drawing up from multi-use vials. Stick the hep C patient, in pulling back a bit ends up in the syringe. Discard needle, syringe is still infected. New needle, old syringe, draw from the vial again, vial is now infected.

You can still get rigid gas-permeable lenses that last basically forever, I wear them every day. You have to take them out at night and clean them, but you only buy them once (unless you damage or lose them, or your prescription changes).

Daily isn't the only option - you can still get monthly lenses.

I share your hate of rent-seeking and subscription culture, but tbf disposable contact lenses are legitimately a nicer product to use. I've done it both ways.

It's not like glass syringes are out of production though? They are still pretty cheap, I get them for $0.50 each from China.

We sterilize plenty of other common tools like scalpels so that doesn't seem like a valid reason. Obviously the disposable design is not even an adequate solution to the risk of cross contamination. I would imagine if it were a real concern you could easily add something like a color changing strip that would indicate whether the needle has been autoclaved since its last use without rendering it useless.

Sounds like the same risk as this situation of reusing them.

Prions aren't destroyed by autoclave