Who is Owl-Eyes in The Great Gatsby by F. Scott Fitzgerald?

Owl-Eyes is a minor character Nick Carraway and Jordan Baker encounter in Gatsby's library when they are attending one of Gatsby's big parties in Chapter Three. Nick describes him as follows:

A stout, middle-aged man with enormous owl-eyed spectacles, was sitting somewhat drunk on the edge of a great table, staring with unsteady concentration at the shelves of books.

The spectacles likely had tortoise-shell rims around the lenses, which would make them resemble an owl's...

Owl-Eyes is a minor character Nick Carraway and Jordan Baker encounter in Gatsby's library when they are attending one of Gatsby's big parties in Chapter Three. Nick describes him as follows:

A stout, middle-aged man with enormous owl-eyed spectacles, was sitting somewhat drunk on the edge of a great table, staring with unsteady concentration at the shelves of books.

The spectacles likely had tortoise-shell rims around the lenses, which would make them resemble an owl's eyes. The man whom Nick will later refer to as Owl-Eyes is examining Gatsby's big collection of expensive books. He is delighted to find they are real books and not fakes. Evidently, he does not believe Gatsby actually reads the books, but he praises him for creating such an impressive and expensive facade. Owl-Eyes tells Nick and Jordan,

"This fella's a regular Belasco."

Owl-Eyes is alluding to the famous producer and playwright David Belasco, signifying that Gatsby spared no expense to put on a spectacular production of his own with his mansion, parties, and everything else. 

Towards the end of Chapter Three, Nick will run into Owl-Eyes again. The drunken man with the huge glasses has crashed his car and can't comprehend why it won't start again. F. Scott Fitzgerald uses this character to illustrate the amount of heavy drinking going on at Gatsby's parties in spite of the fact that the story takes place during the Prohibition Era (1920-1933). 

Near the very end of the novel, Nick is amazed to see Owl-Eyes at Gatsby's funeral. When Nick tells him that hardly anybody else showed up, the owl-eyes man exclaims:

"Why, my God! they used to go there by the hundreds...." He took off his glasses and wiped them again, outside and in.
"The poor son-of-a-bitch," he said.