Not vision like "what I think WWWIII might be like," but vision: how will people with bad eyesight get glasses made if the whole world gets leveled?
What are eyeglasses made of in the first place? They obviously aren't just glass as the name might suggest; nearsighted people can't just look through a window and see what's out in the world clearly. And although eyeglasses in 2005 are probably made of some weird space-titanium-resin or something, Ben Franklin's glasses must have been a simple "something"---but what?
I'm not paranoid about the end of the world, but reading too many science-fiction books has probably filled my head with more questions than the Average Joe. Naturally there would be concerns about energy sources in the post-nuclear age: the electric grid, gas pumps, phone lines. But what about satellite TV? I'm guessing there will be a lot of downtime where there's not much to do, and if any kids survive they will naturally be complaining if there's no 24-hour Cartoon Network available. Even if the energy and the satellites are in order, who's actually working over at Cartoon Network to make sure we get our fix of The Simpsons or Teen Titans? Forget food and clean water, we need our mindless entertainment.
So back to eyeglasses. I wear contacts, so my first thought on this was "Break in and loot all the Walmart optical centers and load up on lenses." Given my penchant for forgetting to change lenses for months at a time, a couple of Walmarts' supply of contacts could probably carry me over pretty far. Maybe I should get laser correction instead---a permanent solution, although it's tough for me to justify laying out a couple of grand now to prepare for the Blade Runner future I might never have to live through.
Eyeglasses have been around a long time, so it can't be that hard to make them. Maybe it's the thickness or the shape of the actual lenses, a friend suggested. Hmmmm. Could there be grinding involved as well? Or layering pieces of glass together?
Things are still in order at this stage in the global game, so maybe I should bone up on a variety of topics in order to prove myself useful in the post-WWIII landscape: eyeglass making, candy production, identification of poisonous snakes. Access to the internet means I can gain this kind of knowledge in the blink of a webpage; perhaps I'll google the phrase "eyeglasses -Lenscrafters +nuclear war +homegrown" and see what I get.