From where? Can I get some? (just kidding)
I assume they get them for free from their cataract surgery, as mentioned by Fear Itself.
Interesting. The “free” sunglasses I’ve received after having my pupils dilated a few times (so I could survive going outside) were remarkably flimsy, not comfortable, and wouldn’t last very long. But yet these cataract surgery glasses seem to be fairly robust, and must at least be somewhat comfortable. This seems to imply that they are designed/manufactured for long term use. This in turn would seem to mean that cataract patients must wear the glasses for an extended period of time.