A woman I know sees this when she casually looks at a book.
Not because she lost her glasses.
She didn't used to. Once, she was an even more prolific reader than I am, every spare minute curled up in the corner of the couch, a mug of cooling coffee next to her, finger holding her place when she looked up. Not a bookmark user, she would leave her books upside down, or memorize (roughly) the page number, flipping back through until she found her spot.
She doesn't see this every time. She can screw her eyes up six ways to Sunday and with the help of her not very helpful glasses, she can do just enough to write a check or review a bill. That effort costs her, and afterwards, she has to "rest" her eyes for a while, leaning back with her eyes closed, battling vertigo.
I would estimate she has a couple thousand books in her house. Stacked haphazardly in bookshelves, closets, her nightstand holds an increasingly dusty stack of brand new books slowly getting older. I think she's managed to slowly work her way through a couple paperbacks... especially heartbreaking to me, as I used to watch her whip through at least one book a day. It's from her I inherited my love for books and freakish speed at reading.
It wasn't even the stroke that did it, although she has a permanent and random case of vertigo from that. No, it was the chemo and/or radiation, exactly which I'm not certain. The treatment that spared Mom's life cost her a huge part of it.
She misses them, her books. She refuses to discuss it, in mourning, I think. People still give them as gifts, and she's gracious, but doesn't share her pain. Her favorite (and only) hobby...cut off completely.
She was the first person I thought of when this topic came up. How to choose? Lisabet very neatly summarized my own feelings on the topic. I'm probably up there close to her 5K books, while 10 years behind in age. I racked up over a thousand on Goodreads in 6 months, so it's most likely even more than that. And to choose one... a Sisyphean task to debate the merits of each one I've read..and haven't yet read.
So the choice of one to save, I would defer to my mom. In hopes that someday, she'll again be able to pick up her choice, and read.