I would like to know the next sentences.
1. You got a bum deal!
2. Let me count the ways.
Dennis thinks the glasses will help with knowing HOW to read, instead of simply helping Mr. Wilson see the letters more clearly. When Dennis still doesn't know how to read after putting them on, he tells Mr. Wilson that he didn't get what he paid for (he got a "bum deal") when he purchased the glasses the help him read. (Get it?)
Mr. Wilson is saying that not getting glasses that made him better at reading is not the only thing that is not ideal in his life. (Having Dennis as his neighbor is a challenge for Mr. Wilson too.)
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.