They came in camouflage, hidden behind dark glasses, but no one noticed them: they only saw shadows.
You see, without the Truth of the Eyes, the Happyfolk were blind."
- You can read your opponent's intent in combat, giving you time to prepare for their next move and revealing feints.
- You can detect lies this way. Lovers will know that the others' feelings are true after their eyes have met.
- If a character is transformed, looking them in the eye will still let you know that it is them. (Can be a form of Red Right Hand for the audience.) Some characters will intentionally hide these behind Opaque Lenses, Scary Shiny Glasses, and Sinister Shades.
- In Angelic Layer, one of Misaki's opponents was able to anticipate all of Misaki's Angel's attacks by watching her. Once Misaki figured this out she was easily defeated.
- In Code Geass, this is how Suzaku catches Lelouch in the lie when the latter implicates that he did purposefully geass his half-sister Euphie into massacring the Japanese.
- In the first case solved in Detective Conan, Shinichi notices the cold eyes of one of the suspects and deduces that he's killed people before. While that guy isn't the murderer for that case, it is revealed that yeah, he has no problem with murdering others. Including, as revealed shortly thereafter, Shinichi himself.
- In Dragon Ball Z after Ginyu steals Goku's body when he first encounters Krillin and Gohan the latter can tell from the look in his eyes that it's not really his father. Likewise, the same is used after the switch is undone, allowing Gohan to confirm that Goku is back to normal.
- Judge Dredd: By the conclusion of "The Judge Child Quest", Dredd has reason to believe that The Judge Child is not all he appears to be, so Dredd looks into his eyes to see if he finds someone who is misguided or a creature of malice. He only sees evil.
- Superman: Secret Origin: Lois is able tell someone's true integrity by looking into their eyes. It's what tells her that Luthor is not the philanthropist he makes himself out to be, that Superman can, in fact, be trusted, and even that there's more to Clark Kent than he's letting on.
- Blade Runner: Replicants don't have human-normal eye reactions to emotion provoking situations. Rather than helping them lie, the lack of reaction is a vulnerability, marking them as a replicant.
- In the 2005 film The Island, after the duo escape from the cloning organ facility they once believed to be their sanctuary and home, while watching TV the heroine is somehow able to tell two identical (both played by Ewan McGregor) characters apart using her ability to tell when one is lying.
- Judge Dredd (1995). Dredd has been arrested for murder with all the evidence against him. His mentor Chief Justice Fargo goes to see him to ask if he did it. The only thing Dredd does is ask (repeatedly) if Fargo believes the accusation. In the end Fargo says, "I just wanted to see it in your eyes."
- The Negotiator — Danny Roman (Samuel L. Jackson) delivers a lecture on facial cues, specifically touching on the tendency of the eyes to look toward the upper left when accessing memory and to the upper right when accessing imagination and making something up. He's rather disconcerted shortly afterward, however, when he tries to use eye cues on an Internal Affairs cop who he believes can clear him, and can see that the guy honestly believes that Roman is guilty of what he's being accused of.
- In the V for Vendetta film, main character Evie can distinguish propaganda cover stories from actual news because the news anchor "Blinks when she knows a story's false".
- There is an Inuit legend about a petrel who is in love with a beautiful maiden, and transforms himself into a man so that he may marry her; however, his eyes are still those of a petrel and so he wears snow goggles to hide them. When the maiden takes them off, she sees his eyes and the spell is broken.
- In The Anubis Gates, Beth Tichy recognizes a monster as her fiancÚ, transformed, by the expression in his eyes — just after she shoots it.
- In the first Artemis Fowl, Root shows two arguing psychiatrists footage of Artemis claiming he can escape the LEP time-stop field, which is supposedly impossible. They put aside their differences and ask to be shown the footage again, zoomed in on Artemis's eyes. They conclude that either he's telling the truth or he's absolutely convinced he is.
- In The Colour of Magic it's stated that gods, no matter how else they may transform themselves, are unable to disguise the true nature of their eyes.
- A similar rule applies to the various transformed creatures in Witches Abroad. For example Greebo, a witch's evil-minded cat, is transformed into a human. As a human he still has the glowing, slitted eyes befitting a cat.
- Experienced conman Moist Von Lipwig of Going Postal notes that he likes the sort of person who looks in one's eye to see their true self, and has a whole gallery of true selves to show them.
- Night Watch plays with the trope: it's noted that unwavering eye contact can make a confident liar stick out.
- A minor plot point in I Shall Wear Midnight is that the Cunning Man has no eyes, just two tunnels leading to the back of his head.
- Slightly more inexplicably, Snuff proves that Vimes can also identify a murderer by eye contact. Because he recognises in their eyes the same thing he sees in his own reflection.
- The Dresden Files: Wizards can read the intimate details of any person's soul just by looking into their eyes, which is called a soulgaze. It has its limitations, though— It Only Works Once, and the target gets to see the exact same things about the wizard. Also it's stressful at best, and can cause a person to Go Mad from the Revelation at worst, especially since one can never ever forget what they see. Wizards tend to avoid making eye contact unless they have a damn good reason to do otherwise.
- In Good Omens, the demon-in-human form Crowley adopts a stylish persona, including Cool Shades that he wears all the time (and gets mocked for by another character). Near the climax, he loses the shades, and it's revealed that at least part of the reason he wore them was that even in human form he still has his real eyes — which are a pair of yellow snake eyes that glow red when he's doing something strenuous.
- Harry Potter and the Prisoner of Azkaban: Harry doesn't believe Sirius Black about his parents' murder until Black, in tears, looks Harry in the eyes and tells him the exact details.
- Throughout the series, Harry is said to "Look a lot like your dad, but you have your mothers eyes." Later in the series, we find out that Harry's resemblance to his father is mostly superficial (Physically and personality-wise), and that ultimately, he is much more like his mother.
- All over the place in the Honor Harrington series, where stoic naval officers with otherwise perfect poker faces give away their inner worries or kindness (e.g. Honor Harrington herself), and sociopathic villains give away the hollowness inside.
- The only noted exception to this is Eloise Pritchart, the People's Commissioner for Admiral Javier Giscard and future President of the restored Republic of Haven. Her eyes never betray her inner feelings. Given that she's in a romantic relationship with Giscard and they're plotting a coup d'etat, this is definitely a good thing.
- The Man Who Was Thursday plays with the "wearing Sinister Shades to disguise his true nature" version of the trope, with a sinister character whose dark glasses prompt speculation about what horrors his eyes would reveal if they were visible. Ultimately, it's revealed that not only are his eyes entirely normal, they proclaim his true — kind and friendly — disposition, so he had to hide them in order to appear sinister.
- The Moomins: In one terrifying scene, the characters find a magic hat that transforms things. Moomintroll tries it out of curiosity and is turned into a hideous monster. None of his family members recognize him, but in the end Moominmamma can still tell that it is him by staring into his eyes.
- A Song of Ice and Fire: Littlefinger is an extremely accomplished liar and manipulator, able to deceive almost anyone. Only Sansa Stark of all people takes note of his "grey-green eyes that did not smile when his mouth did."
- In Soul Screamers, the eyes are literally the windows to the soul, and people with no soul have only blank white eyes. However, they can use contacts to hide this.
- An episode of Buffy the Vampire Slayer invokes this when Giles is turned into a demon; Buffy recognises him by looking him in the eyes and noting that no one else could look as annoyed with her. Lampshaded when Buffy suffers a Grand Theft Me later on.
"Giles, you turned into a demon and I knew it was you! I mean, can't you just look in my eyes and be all intuitive?"
- Doctor Who: River looks into the Doctor's eyes for this reason in the finale of Season 6.
- How I Met Your Mother lampshades this in "The Exploding Meatball Sub."
Ted: Lily, the downside to having giant Japanese anime eyes is that they're easy to read, and right now yours are screaming, "What about my trip to Spain, deadbeat?"
- Lie to Me: Dr. Cal Lightman and the rest of the Lightman Group use microexpressions (a minute form of facial movements) and body language to determine whether or not someone is telling the truth. Cal, Gillian, and Loker studied for years to learn it. Torres is a "natural", one of something like 5% of the population who has the ability to spot deception.
- On NCIS Kate claims she could tell if a person was good by looking into their eyes, but was not very good at it as she accidentally helped a bomber blow up the place where she had worked, then let the terrorist who later tries to kill her go because there was good in their eyes.
- In the Sanctuary episode "Animus" Henry undergoes a psych evaluation. He is asked how he would feel if he'd see a wounded animal in the woods and the wind carries the scent of blood to his nostrils. He answers "sad", but his pupils widen (often a sign of arousal, excitement or pleasure), betraying his HAP nature.
- In Stargate SG-1, Bra'tac demonstrated on several occasions the ability to almost perfectly tell if someone was lying by looking deep into their eyes. Even when the person in question has convinced their closest friends and lie detectors, Bra'tac is not fooled.
- In the episode "Folsom Prison Blues" (S02, Ep19) of Supernatural, Dean asks his lawyer to look in his eyes and decide if he is guilty.
- Stephen Foster's song "In The Eye Abides The Heart".
- "Fire Coming Out of the Monkey's Head" by Gorillaz takes it to an extreme: the Happyfolk are so dependent on the "Truth of the Eyes" that they are unable to even see people with covered eyes. It's probably a metaphor for dangerous innocence.
- Subverted in Legend of the Five Rings — one of the Scorpion samurai mentions that lying with their eyes is one of the first things the youth learn in his clan.
- In Fire Emblem: The Blazing Sword, Wallace declares Lyn trustworthy and joins her cause after getting one good look of her eyes.
Wallace: I've been a knight for 30 years, and there is one thing I learned. A person with eyes as bright and true as yours is no deceiver.
- In Metal Gear Solid, Snake tells Meryl that she never shot someone from the way her eyes constantly wander off.
- In the first Lands of Lore the villain of the game, Scotia, possesses powerful shapeshifting magic, but her eyes always remain the same colour. Conveniently, she is apparently the only human being in the game's world who has yellow eyes.
- In The Wolf Among Us, there is Bigby Wolf, who is the fabled Big Bad Wolf that can take on a human disguise (or glamour). Even in his human form, when he is in dim light, his eyes often glow an otherworldly yellow color and appear more bestial.
- In Apollo Justice: Ace Attorney, Apollo uses his bracelet to see through Machi's eyeglasses during a trial to determine that he's lying.
- In The Order of the Stick this becomes a plot point. Blind Pete is able to betray Haley because she relies upon this to sense motivations.
- Disney's Beauty and the Beast — that's how Belle realizes that skinny prince is really her Beast.
- In Codename: Kids Next Door: The characters can distinguish between their friends and their friend's evil counterparts from the Mirror Universe (during Operation P.O.O.L) by looking into their eyes.
Eizzil: They can tell who people are in this world by looking at their eyes!Wally: It's called being a friend!
- Subverted in The Emperor's New Groove. Pacha refuses to make a deal with Kuzco unless he looks him in the eye and means it. He fails to notice that Kuzco is playing him for a sucker until he's hanging above a chasm.
- On Gravity Falls, Dipper has yellow eyes when Bill Cipher takes over his body, though the characters themselves never seem to notice.
- In Rango, Rattlesnake Jake says that Rango won't shoot him because he doesn't have a killer's eyes. In round two, Jake gets an Oh, Crap moment after Rango has had his act together and is willing to kill.
- Subverted in The Simpsons.
Homer: Look me in the eye boy, and tell me you didn't do it.Bart: I didn't do it.Homer: Why you little...!Throttles BartHomer: How dare you look me in the eye and lie like that!
- While not foolproof by any means, eye movements and how someone looks at you can often be an indicator if they are lying to you or not. However, skillful liars can control this to an extent.
- It should be noted that many people, knowing the stereotype of liars being unable to maintain eye contact, will do the opposite, and actually make more eye contact when they're lying. The best way to spot when someone's lying is to be alert for a change in behaviour, rather than any specific action on its own.