Canthal tilt
Canthal tilt describes the slope between the inner and outer eye corners. The tilt is positive when the outer corner is higher, neutral when the corners are level and negative when the outer corner is lower.
+4.76°
The slope between the eye corners
the average angle from the inner to outer eye corners.
The points mark each eye's inner and outer corners.
What different angles look like
The outer eye corners slope upward in all three examples. From left to right, the slope increases and the outer ends of the eyes look more lifted. The final sequence shows another face with the original portrait in the centre.
Changing eye-corner slope
Face B
Corner direction and eyelid shape
The canthi are the points where the upper and lower eyelids meet at each end of the eye. The line joining them gives the eye opening its overall direction. Follow that line when judging tilt; the curve of the upper eyelid can rise above it even when the corners are level.
Negative, level and positive tilt
With negative tilt, the lower outer corner gives the eye a downward turn. That turn can be more noticeable when the eyelid contours also descend towards the corner. Level corners give the eye a horizontal direction, but the opening can still look rounded if the upper lid arches high above the iris.
Positive tilt raises the outer end of the eye. A slight rise can be subtle beside a strongly curved upper lid. At a steeper tilt, the difference in corner height becomes easier to see, giving the opening a more pronounced upward direction.
Corner height and eye width
The angle depends on the height difference between the corners relative to their horizontal separation. The same difference in height makes a steeper line across a short opening than across a long one.
The reported result averages both eyes. Matching slopes can produce the same average as a more positive slope on one side and a level slope on the other.
Eye-opening shape and brow direction
Positive tilt in a long, low eye opening can give it an elongated, upturned shape. A taller opening with the same tilt looks rounder while still rising at the outer corner. A short opening with little height may look narrowed rather than elongated. Eye width and opening height help distinguish these shapes when the tilt values match.
The curve of each lid also affects which parts of the iris are visible. Two eyes can have the same corner slope and central opening height but differ towards their outer ends: one may taper gradually, while the other stays rounded until close to the corner.
Above the eye, a rising brow tail can reinforce the upward direction. A horizontal brow contrasts with it. A level eye can also sit beneath a rising brow, so an upward sweep across the eye region does not necessarily come from the eye corners.
Eye-corner height and attractiveness
Kempa and colleagues asked 2,081 adults to rate nine versions of one unisex face with changes to eyebrow and outer-corner height. Raising the outer corners reduced attractiveness ratings among those alternatives. The experiment tested edits to one face; it does not establish a preferred tilt in degrees across different eye shapes.
Changes in the eye region with age
Sforza and colleagues documented age-related differences in eye-region dimensions. Flores and colleagues found shorter horizontal openings with age alongside changes to lid and crease geometry. These changes can alter the appearance around the eye corners even if their slope stays similar.
How we measure it
We measure the slope between the inner and outer corners of each eye, then average the two angles.
- 1
Mark the inner and outer corner of each eye where the eyelids meet.
- 2
Measure the slope of each eye-corner line and average the two angles.
Getting a clear photograph
- Looking up or down changes the apparent slope of the eye corners.
- Squinting or deliberately widening the eyes changes the eyelid shape.
- Liner, lashes and shadow can hide the true eye corners.
- Keep the camera near eye height and look directly into the lens.
Check the marked points
- Check that the four corner points sit where the eyelids meet.
- Inspect each eye separately. Keep correctly placed points even when the slopes differ.
- Keep your head upright.
- Retake the photograph if either eye is partly closed or the head is angled up or down.
Measure your canthal tilt
Upload a front-facing photograph to see your result and review the marked points.
Sources
- 1 Understanding the impact of eyebrow and lateral canthal height on the perception of character traits: A rating-based analysis of 2081 participants
Tests nine edited versions of one unisex face. Outer-corner elevation reduced attractiveness ratings in this experiment; it does not establish universal degree thresholds.
- 2 Age- and sex-related changes in the soft tissues of the orbital region
Documents age and sex differences in eye-region dimensions; orbital dimensions are not interchangeable with central eyelid-opening height.
- 3 Quantitative 3-dimensional Geometry of the Aging Eyelids
In 46 white women, eye-opening width and height decreased with age, with width decreasing faster. Relative roundness need not mean a larger eye opening.
- 4 Anthropometric analysis of canthal tilt and related periocular measurements
Provides measurement context and documents variation in canthal orientation.
- 5 Reliability of measurements taken from facial photographs
Explains how photographic setup and landmark placement affect facial measurements.
