An eye loupe is a small magnifying device worn over the eye to see tiny details closely. It is commonly associated with jewelers, but is used by many other professions, from watchmakers to engineers of small electronics, and for appraisal of precious gems, coins or stamps.
In fiction, someone wearing an eye loupe is used as visual shorthand for several things. If it's a one-shot, never-seen-before character, this immediately tags them as some sort of expert coming to appraise whatever valuable artwork or rarity is at hand.
Otherwise, an established character pulling out one is a sign that they're Crazy-Prepared, or more commonly, greedy. The Miser Advisor or The Scrooge frequently owns one, ready at all times to appraise the value of anything they grab.
An eye loupe can also show up for quick gags and humorous situations, often in a completely unexpected setting (including anachronistic). A common stereotype is for a woman offered an engagement ring to immediately examine it with a loupe. Or the humor might be in establishing something is very, very small and requires the tool to be seen.
- In the Ranma ½ manga, Nabiki Tendō wears an eye loupe to appraise the "engagement ring" Ranma's mother tasked Ranma to give to his fiancée. Nabiki deems it of no monetary value, which doesn't change its symbolic value. Turns out, it isn't an engagement ring at all, although for once that's not because Nabiki was deceptive about it.
- My Little Pony: Friendship is Magic (IDW): In "Manehattan Mysteries", Rarity is seen using a loupe to confirm that a diamond is fake.
- Wonder Woman (1942): The appraiser who lets Diana know that someone is trying to sell gems that fit the description of the stolen Paradise Island Royal family jewels has an eye loupe sitting on his desk.
- Played with in Alice in Wonderland, where the Mad Hatter uses a salt shaker as a loupe to examine the White Rabbit's watch.
- Despicable Me 3: In Paris, a renowned gem expert examines the Dumont Diamond with an eye loupe to make sure it hasn't been replaced by a fake. Except he's in fact Balthazar Bratt in disguise, and the eye loupe can shoot Tranquillizer Darts with which he neutralizes the guards and curator.
- The Secret of the Hunchback: Frollo uses one to examine one of the church's goblets. Like other things in this movie, it's anachronistic.
- In the mine scene in Snow White and the Seven Dwarfs, Doc is shown using a loupe to inspect the gems the dwarfs have mined.
- In Armageddon, Rockhound uses an eye loupe to seduce a young wife by telling her the diamond her husband gave her is fake.
- In a sketch from The Benny Hill Show with Benny Hill as Robin Hood, he's about to kiss the hand of a wealthy lady when he notices the many jeweled rings and bracelets she's wearing. Robin pulls a (completely anachronistic) eye loupe to better examine them, before robbing her blind.
- Doctor Who: In "Heaven Sent", the Twelfth Doctor picks up an eye loupe conveniently placed next to a painting of Clara Oswald to examine it. It allows him to find out the puzzling fact that the painting is very old, despite his instincts telling him he hadn't traveled through time. Then he drops the eye loupe to test out the gravity of the place.
- In Last Window, Kyle borrows one from Dylan, who uses it as part of his crystal collection hobby, in order to view an important detail on a ring.
- The Handbook of Heroes: The elf Wizard offers his tiefling girlfriend a priceless heirloom cloak... and she pulls out an anachronistic eye loupe. (She's a Thief, so it's to be expected.)
Thief: So... if you had to translate "value beyond measure" into gold pieces?
- The Order of the Stick: A gnome artificer uses an eye loupe to examine the Ioun Stone Blackwing has seized from Laurin Shattersmith in the previous book.
- Avatar: The Last Airbender, "Avatar Day": While doing the whole detective shtick, Sokka wears one when investigating the giant footprint of Avatar Kyoshi.
- In some old Donald Duck cartoons, Daisy Duck would be the one to use the loupe to check jewelry (like an engagement ring from Donald), for instance Donald's Diary (at 4:38 on the video).
- Duckman: In the episode "Pig Amok" Cornfed offers Bernice a diamond ring. Bernice accepts it and immediately checks it with a loupe.
- Unsurprisingly, Scrooge McDuck owns a loupe which he uses to appraise valuables. Notably in DuckTales the Movie: Treasure of the Lost Lamp, with the treasure of Collie Baba.
- In the DuckTales (2017) reboot, Louie Duck, the treasure-obsessed triplet, wears a loupe on a chain around his neck should he need to inspect any gold or gems he comes across while adventuring.
- In "Where the Buggalo Roam", when the bead the native Martians traded their land for turns out to be a giant diamond, Bender pulls out a loupe to examine it. He does so again in "Bender's Big Score, Part IV", after realizing a phony diamond he switched with a real one may have been worth more.
- One imagines he acquired it sometime after "A Flight to Remember", in which Hermes uses one to determine that a diamond bracelet Bender was left by a tragically dead Love Interest is a fake.
- In the Looney Tunes short "Goo-Goo Goliath", the drunk Delivery Stork switches off the families of a human baby and a giant baby (because the giant one was too heavy to fly to the top of the beanstalk). At the end, we see the adult giant taking care of the human baby, using an eye loupe to change his diapers.
- My Little Pony: Friendship Is Magic:
- "Castle, Sweet Castle": Twilight Sparkle is seen wearing one in the flashback of her rearranging Rarity's gems. She spent a whole afternoon with one of these.
- "Rock Solid Friendship": Maud Pie is wearing an eye loupe to examine the emerald jasper she found... while inside a quarray's eel mouth.
- "Student Counsel": As a quick visual gag, Mudbriar is seen examining a stick with an eye loupe as they traipse through the Everfree Forest.
- "Dragon Dropped": Rarity is seen several time examining gemstones with an eye loupe, both in flashback and present.
- Scooby-Doo: Scooby-Doo does this a couple of times, primarily because he's the most likely candidate to pull off Hammerspace gags for a joke.