I can see it in their eyes—THEY'VE ALREADY DIED INSIDE.

I think the shape of your eye can be fucked up too, so the lens focuses on the image but then it doesn't, like, line up in focus with your retina? Anyhow if most people with vision problems just had problems with fatigue than I don't see how you could constantly see things the same bad way day after day, you'd think you'd get horrible variations with some days where you could almost see and then other days where no you can't.