If there's a sort of "apocalyptic" event but there are still surviving communities, will people be able to make eyeglasses again, or are people with vision issues gonna be fucked?

People who wear glasses are screwed but not as screwed as people who rely on medication.

https://www.engineeringforchange.org/solutions/product/adspecs/

Hopefully if enough of these get distributed it won't be so much of a problem except for people with astigmatism.

https://www.epo.org/en/news-events/european-inventor-award/meet-the-finalists/joshua-silver

Joshua Silver, a professor of physics at the University of Oxford, first had the idea to manufacture adjustable lenses for the poor, removing the need for expensive equipment and professionals, in May 1985 after he had created a variable focus lens out of curiosity.

His invention allows wearers to adjust the glasses to their personal prescription without the assistance of a healthcare professional. They simply look at a reading chart and adjust the glasses until they can see the letters clearly.

The glasses use durable but flexible plastic lenses, which have fluid sacs filled with silicone oil between them. These glasses can easily be adjusted by the wearer by simply adding or removing some of the oil in the sacs.

The invention is not without its limitations, however. Currently, the principle only functions successfully with circular lenses, limiting the design opportunities. Additionally, the principle can only alter the magnification of objects, so the glasses cannot treat those with astigmatism. What these spectacles lack in aesthetics, however, they make up for in spades with utility and work on non-round lenses is already underway.

His stated goal was to make the overall cost of a pair of glasses as low as $19.

Not that useful in scenarios besides reading: if you curl your hands in front of your eye and leave a very tiny opening you can create a pinhole that'll make a tiny bit of your view in focus

Photo from Minute Physics demonstrating what you need to do for that:

https://youtu.be/OydqR_7_DjI

Your screwedness depends on how bad your eyesight is. Can you see well enough to tell a weed apart from the crop you're growing when looking at arms length? Then that's all the eyesight you need to be useful to a community

Our modern life involves a lot of reading and writing and sometimes very technical work. But the work of surviving on planet earth is a little less vision intensive: farming, cooking, childcare, handcrafts. Depending on how bad your vision is you might even be slow and shitty at these, but people can adapt to a lot and figure out how to perform tasks they’ve done before, even with poor vision. Look at the blind: they can be functional. Yes there are things like hunting which you could. not. do. with poor vision but that’s why we live in tribes. Someone younger with better eyes will do that while you shell nuts all day.

Eye glasses started showing up around 1300 AD. Implies the basic tech / processes required to make them is relatively simple, given that they've been around in some form ever since the middle ages. Granted, they wouldn't be as sophisticated as they are today, and many people with very niche issues would suffer.

Anything more modern, requiring microchips or heavily integrated international supply chains would go poof. Personally, I'd worry about dental and medical stuff we diagnose with x-rays. Like it's not too uncommon for people to have a root canal these days... but it didn't become a more 'common' thing until around the 1800-1900 period. Hell, getting your wisdom teeth pulled in a post-event world would likely suck some serious ass.

You can make a rough magnifying lens by trial and error using glass and a hand grinder—not the same as prescription lenses, but for many it would be better than nothing.

It took centuries to get to disposable contact lenses while trying to figure out the physics, both in optics and in manufacturing any sort of spectacles, at the same time.

Will the survivors of the apocalypse be able to pick up where we left off or will they essentially start from scratch? That depends on the apocalypse and on the survivors. Do documents and knowledge survive, perhaps in a stash or in digital form? Do the survivors include an optician or a material engineer? Chances look good if that's the case. If no, life will get a lot harder for many people.

Maybe contact lenses are apocalypse proof

You'll have to hit up the local glasses stores. Luckily there's plenty of em.

You'll be okay, OP. It will be extra shitty though. Imagine running from a horde of cannibalistic raiders and you drop your glasses...

If you have or can scavenge a laser pointer, just go hog wild shining it all around in your eyes. You have nothing to lose trying it at that point and maybe you get lucky and give yourself DIY lasik.

One would think that if most of society is toast there will be a shitload of left over glasses that could be collected and then distributed to those in need.

For myopia, only an issue for a couple of generations. If we’re living off the land again, myopia will stop being a thing as in the past.

I once lost my glasses and used an ordinary drinking glass as a monocle as substitute. It wasn't perfect, but good enough for me to find my glasses. (This was before cell phones had cameras).

Having been very near sighted for most of my life, I've come to the conclusion that it's not really that big of a handicap. It's mostly an issue for reading things, and even that can be done when putting it close enough.

I can't really think of anything in a hypothetical apocalypse where 20/20 vision would be absolutely necessary.