The movie title is drawn from a passage in Edgar Allan Poe's "The Tell-Tale Heart" (1843): "One of his eyes resembled that of a vulture - a pale blue eye, with a film over it. Whenever it fell upon me, my blood ran cold; and so by degrees - very gradually - I made up my mind to take the life of the old man, and thus rid myself of the eye for ever."
Edgar Allan Poe attended West Point for a while around 1830, and had already seen the first of his poetry published.
The pub owner is named Benny. This marks the tavern as "Benny Havens" a well-known and long-run establishment in the village of Buttermilk Falls (now Highland Falls), adjacent to West Point. The tavern existed from the earliest days of the Academy and as of this movie's release, a bar using this historic name still exists in Highland Falls, NY.
In a 2023 interview with The Gate, Scott Cooper spoke about bringing the story to Christian Bale 10 years prior and why it ended up being right to wait those intervening years before making the film: "Christian grew perfectly into the world-weary detective, because he was a bit too young at the time. And he was too old to play Edgar Allan Poe. And he and I then went off to make a western called Hostiles (2017), and I made a couple of other films, and then I dusted this off and I re-sent it to him. Tailored it for him as he had aged and I'd got to know him and our friendship deepened, and he said, 'Man this is bloody good, let's make it!' and off we went."
Although the film is set in the USA and the characters are American, most of the cast is British.