Harmony & facial ratios
Eyes & brows: the seven measurements
7 min read · Updated November 1, 2026
Seven measurements cover the eyes and brows: the tilt and shape of the eye, how far apart the eyes sit, and the length, tilt and height of the brow.
How these fit together
Most of these are angles or ratios of small distances, so a few pixels of landmark error matters more here than for the thirds. Expression moves them too: a squint changes eye aspect ratio, and a raised brow changes brow height and tilt. A relaxed, neutral face with the eyes open normally gives the cleanest reading.
Lateral Canthal Tilt
The angle of the line from the inner to the outer corner of each eye.
What it is
Canthal tilt is the angle between the inner corner of the eye and the outer corner. If the outer corner sits higher, the tilt is positive (upturned); level is neutral; lower is negative (downturned).
How it's measured
The inner and outer corner of each eye are landmarks. The angle of each eye's corner-to-corner line against the horizontal is taken in a levelled frame and the two are averaged.
Definition: the angle, in degrees, between the horizontal and the line from each eye's inner corner to its outer corner, averaged over both eyes. Positive when the outer corner is higher.
How it's read
A mild positive tilt reads as alert and youthful, and women are generally scored toward slightly more tilt than men. A neutral tilt is common and fine. A clearly negative tilt can read as tired, though many striking faces have it.
What affects it
Head roll is the biggest distortion, which is why the measurement levels the eye line first. Eyelid shape, brow position and under-eye puffiness change how the tilt looks without changing the corners themselves.
For more detail, see the full guide: Canthal tilt.
One Eye Apart Test
The gap between your eyes compared with the width of one eye.
What it is
The one-eye-apart test asks whether the space between your two eyes is about the width of one eye. A value near 1 matches the traditional rule; higher means the eyes sit further apart, lower means closer together.
How it's measured
The gap is the distance between the two inner corners of the eyes. The eye width is taken from the inner corner to the end of the upper-lid hood and averaged over both eyes. The ratio is gap divided by eye width.
Definition: the gap between the inner eye corners, divided by the width of one eye from its inner corner to the end of the lid hood, averaged over both eyes.
How it's read
Values close to 1 are read as well-spaced eyes. Wide-set eyes (higher) can look youthful and open; close-set eyes (lower) can look intense. Neither is a flaw on its own, and it is a soft rule rather than a hard one.
What affects it
Eye width depends on how open your eyes are and where the lid hood ends, so squinting, glasses or heavy lids change it. Look straight at the lens with relaxed, fully open eyes.
Eye Aspect Ratio
The width of the eye divided by how far it opens; how almond or round the eye is.
What it is
The eye aspect ratio compares an eye's width with its opening height. A higher number is a wider, narrower-slit eye; a lower number is a rounder, more open one.
How it's measured
Eye width runs from the inner to the outer corner, and opening height from the top of the upper lid to the bottom of the lower lid, both from landmarks, averaged over the two eyes.
Definition: eye width divided by eye opening height, averaged over both eyes.
How it's read
Women are generally scored toward rounder, more open eyes and men toward a narrower, more almond or hooded look, which is why the ranges differ by sex. The extremes on either side read as either very intense or very doe-eyed.
What affects it
This is one of the most expression-sensitive ratios. A smile, a squint or tired eyes narrow the opening, and a startled look widens it. Relax your face, blink just before the shot and look straight ahead.
Eye Separation Ratio
The distance between your pupils as a percentage of your cheekbone width.
What it is
This compares how far apart the pupils sit with how wide the face is. It places the eyes on the face: closer together, centred, or wider apart.
How it's measured
Pupil distance is divided by cheekbone width and multiplied by 100. Both are landmark distances in a levelled frame.
Definition: the distance between the pupils, divided by cheekbone width, × 100.
How it's read
On most adult faces the pupils sit at about the mid-40s percent of cheekbone width. A noticeably lower figure means closer-set eyes and a higher one wider-set eyes, relative to the face.
What affects it
Because it uses face width as the reference, a wide-angle selfie distorts it. A neutral, level photo from a normal distance gives the most reliable figure. Where you look matters too: crossing or drifting eyes shift the pupil points.
Eyebrow Tilt
The angle of each brow from its inner end up to its highest point.
What it is
Eyebrow tilt measures how steeply the brow rises from the inner end near the nose to its peak. A flat brow is near 0°; a rising, arched brow has a higher angle.
How it's measured
The line from the brow head to the brow arch is compared with the horizontal in a levelled frame, for each brow, and the two are averaged.
Definition: the angle, in degrees, between the horizontal and the line from each brow's head to its arch, averaged over both brows.
How it's read
Brow shape is one of the clearest sex-linked traits, so the ranges differ: straighter, flatter brows are the more masculine norm and a more arched, rising brow the more feminine one. Moderate tilt reads as natural and expressive on both.
What affects it
Expression changes brow angle instantly: raised brows steepen it, a frown flattens it. Grooming changes the visible shape, and the measurement follows the brow you actually have in the photo, so keep your face neutral.
Eyebrow Low Setedness
How close your brows sit to your eyes, compared with the size of the eye opening.
What it is
Brow set describes the distance between the brow and the eye. Low-set brows sit close above the eyes and give a deep-set, intense look. High-set brows leave more open space and read lighter and more open.
How it's measured
The vertical distance from the inner end of the brow to the pupil line is divided by the open height of the eye. A lower number means a lower, closer brow.
Definition: the vertical distance from the brows' inner corners down to the pupil line, divided by the open height of the eye.
How it's read
Lower-set brows are generally read as more masculine, and higher-set, more open brows as more feminine, so the ranges differ by sex. Extremely low brows can look heavy and extremely high ones surprised.
What affects it
Raising or lowering your brows in the photo changes this a lot, so keep them relaxed. Brow grooming, particularly shaping the lower edge, changes how low the brow looks.
Brow Length to Face Width Ratio
The combined length of both brows compared with the width of the face.
What it is
This measures how much of the face's width the brows span. It captures whether the brows look short and neat, or long and extend toward the temples.
How it's measured
Each brow is measured horizontally from its inner corner to its tail, the two lengths are added, and the total is divided by cheekbone width.
Definition: the horizontal length of each brow, from its inner corner to its tail, added together and divided by cheekbone width.
How it's read
Brows that reach roughly the outer corner of the eye and give the upper face a balanced frame read well. Very short brows can leave the eye area looking bare, and very long ones can dominate it.
What affects it
This reflects the brows as they are, including gaps or sparse tails that landmark placement may cut short. Brow grooming and filling change how long they look and are the most direct lever.
See it on a full report
Open the sample report to see every measurement, score and highlight on a real example.