Who is Owl-eyes? What surprises him about Gatsby"s library? why would this impress him?

Owl Eyes is a party guest. He is shocked that the books in Gatsby's library are real.

“Absolutely real — have pages and everything. I thought they’d be a nice durable cardboard. Matter of fact, they’re absolutely real. Pages and — Here! Lemme show you.”

Taking our scepticism for granted, he rushed to the bookcases and returned with Volume One of the “Stoddard Lectures.”

“See!” he cried triumphantly. “It’s a bona-fide piece of printed matter. It fooled me. This fella’s a regular Belasco. It’s a triumph. What thoroughness! What realism! Knew when to stop, too — didn’t cut the pages. But what do you want? What do you expect?”