How to Smile with Your Eyes: The Smize Technique Explained

Smiling with your eyes refers to the activation of the orbicularis oculi — a ring-shaped muscle that encircles the eye socket. When it contracts, the lower eyelids rise slightly, the outer corners of the eyes crinkle, the cheeks lift upward, and the entire upper face lights up. This is the defining visual signature of a genuine, felt smile.

Most people only smile with their mouth. The corners lift, the teeth may show, and the expression is technically a smile — but the eyes stay flat and neutral. Observers sense this absence instantly. The brain is calibrated to read the upper face as the authenticity signal; a mouth smile without eye involvement reads as performative at a biological level.

The term smize entered mainstream vocabulary in the mid-2000s through modelling culture, but the science behind it was documented by French neurologist Guillaume-Benjamin Duchenne in 1862. He called the orbicularis oculi engagement the 'sweet emotions of the soul' — the one facial marker that cannot be fully faked on command.

The orbicularis oculi has two portions. The inner portion (pars palpebralis) controls normal blinking and is fully under voluntary control. The outer portion (pars orbitalis) — the part responsible for the eye squint in a genuine smile — is largely involuntary. It responds naturally to positive emotion but resists deliberate activation for most people.

Paul Ekman, who developed the Facial Action Coding System (FACS) in the 1970s, catalogued this as Action Unit 6 (AU6): the cheek raiser driven by the outer orbicularis oculi. Combined with AU12 (the zygomatic major pulling the lip corners up), AU6+AU12 together constitute what Ekman formally classified as the Duchenne smile — the most reliable marker of genuine positive affect in human facial expression research.

The practical implication is that you cannot force a genuine smize the same way you force a mouth smile. But you can train the neural pathway that connects intent to orbicularis oculi activation — and you can create the emotional conditions that trigger it naturally.

Exercise 1 — The isolated cheek raise: Stand in front of a mirror and, without moving your mouth, attempt to raise your cheekbones upward as if smiling hard with just your cheeks. Initially this feels disconnected and odd. You are targeting the lower portion of the orbicularis oculi indirectly by engaging the zygomatic muscles without involving the mouth. Do 10 reps, holding each for two seconds. Over two to three weeks, the eye engagement becomes more responsive.

Exercise 2 — The memory trigger practice: Choose a specific happy memory that reliably produces a genuine smile. Deliberately recall it in front of a mirror and watch what happens to your eyes. The goal is to train yourself to access this memory quickly and observe the eye engagement it produces. Over time you can summon this eye engagement on command by accessing the memory pathway.

Exercise 3 — The half-smile hold: Produce a very small, gentle mouth smile — barely noticeable — and hold it for five seconds. This low-intensity expression often allows the orbicularis oculi to activate more naturally than a forced full smile. Notice whether your eyes change. This subtle expression frequently produces more genuine eye engagement than a wide deliberate smile.

A simple self-test: cover the bottom half of your face in the mirror, leaving only your eyes visible. Now think of something genuinely funny or recall your go-to happy memory. Do your eyes change? Do the lower lids rise slightly, the outer corners crinkle, and the area just below the eyes fill out? If so, your smize is active.

Now try smiling on command — deliberately, without emotional connection — and cover the bottom half again. For most people, the eyes remain largely unchanged: flat, neutral, slightly wider from the effort of smiling but without the warmth and narrowing of the genuine version.

This test reveals exactly what observers see when they look at you. The upper half of the face carries the emotional signal. If you can train your upper face to match your lower face, every smile you produce will read as genuine and warm regardless of the situation.

Photos capture a frozen millisecond and strip away the motion, sound, and context that make real-time expressions feel alive. In that frozen frame, the eyes are disproportionately important. A photo where the eyes show genuine engagement reads as warm, confident, and attractive. A photo where the eyes are neutral reads as tired, distant, or posed — regardless of what the mouth is doing.

Portrait photographers have known this for decades. The direction 'think of something you love' is standard precisely because it triggers the limbic pathway that activates the orbicularis oculi. What the photographer is actually trying to produce is eye engagement — the smize — not a specific mouth shape.

For Smile Tracker analysis, eye engagement is read through four specific blendshape values: cheekSquintLeft, cheekSquintRight, eyeSquintLeft, and eyeSquintRight. These directly measure orbicularis oculi activation. A photo with strong eye engagement will score significantly higher than an identical photo with neutral eyes, even if the mouth smile is identical.

The smize is not a squint. Squinting involves the upper lid descending and narrowing the eye opening from above — this reads as suspicious, uncertain, or tense. The smize activates the lower lid and the outer corners — the effect is a gentle narrowing from below and the sides, with the upper lid remaining naturally open.

The distinction matters because people who try too hard to add eye engagement often over-contract and produce an uncomfortable tense squint rather than a warm smize. The correct feel is a gentle raising of the cheeks — almost as if you are inhaling a wonderful smell — with the eye narrowing happening as a secondary effect of the cheek movement, not a primary deliberate squeeze.

If you are unsure whether you are getting the right muscle: practice the half-smile exercise and let the eye engagement build naturally from the gentle cheek lift. This produces the correct orbicularis oculi activation without the upper-lid tension of a full squint.