Midface ratio

The pupils define a horizontal span across the centre of the face, while the upper lip marks the bottom of the measured region. Comparing those distances describes the proportions around the nose and philtrum. Near a ratio of one, pupil spacing and eye-to-lip height are similar.

The features inside this region can occupy its space differently. A tall nose followed by a short philtrum may place the upper lip at the same level as a shorter nose followed by a long philtrum. Their midface ratios can match even though the spacing immediately above the mouth looks different.

A low ratio can reflect more height between the eyes and upper lip. With pupil spacing unchanged, a lower upper-lip position extends the measured region vertically. A tall nasal region or a long philtrum may contribute to that distance, so looking at each helps locate where the extra height occurs.

Closer pupils also lower the ratio, even when the vertical distance is ordinary. The centre then looks narrow rather than particularly long. This arrangement can sit within narrow cheeks or inside a much broader face, where the eyes may appear concentrated towards the middle.

When limited pupil spacing accompanies greater eye-to-lip height, both dimensions contribute to an elongated impression. Broad cheekbones can still surround that narrow interior. A face can therefore look wide across the cheeks and long between the eyes and mouth at the same time.

Wider pupil spacing raises the ratio by adding horizontal span. That spacing may come from long eye openings, a larger gap between them, or a combination. Long eyes around a modest gap fill more of the region than short eyes separated by a wide gap, despite potentially similar pupil distances.

A shorter eye-to-lip interval raises the ratio by bringing the upper lip closer to the eye line. The centre may look compact without the eyes being widely spaced. This compactness can occur within a short face, or beneath a tall forehead and above a long chin. The ratio describes the interior arrangement while those surrounding regions determine the full facial height.

Pupil-to-face width helps assess how widely the eyes sit within the cheeks. If it is low alongside a low midface ratio, limited pupil spacing may contribute to both results. The eye openings and inner-corner gap then show whether that limited span comes from smaller eyes or closer placement.

The middle third covers the nasal root to the nasal base, so it helps locate nasal height within the larger eye-to-lip interval. A large middle-third share can accompany a near-square midface ratio when pupil spacing is also broad. Conversely, a short nasal region followed by a long philtrum can leave substantial height between the eyes and upper lip.

Cheekbone width supplies another comparison through fWHR. Broad cheeks can raise fWHR while close pupils keep the midface ratio low. This difference describes a broad outer face around a narrow central arrangement, rather than conflicting readings of the same shape.

Eye-to-mouth angle uses the pupil span too, but ends at the closed-mouth seam instead of the top of the upper lip. Upper-lip height separates those endpoints. A taller visible upper lip can therefore deepen the eye-to-mouth triangle without an equivalent change in the midface measurement.

Pallett, Link and Lee changed eye and mouth spacing within the same faces and found that the edits affected attractiveness ratings.

Their experiment expressed spacing relative to facial width and height rather than testing this exact midface ratio. The 0.97–1.02 reference describes a near-square relationship, but its endpoints are not established preference boundaries.

Eye-region dimensions and central facial height develop at different rates. As the face matures, the distance down to the upper lip can increase more than pupil spacing, lowering the ratio. Velemínská and colleagues also associated larger adult faces with greater elongation, so facial size may accompany differences in shape.

In adulthood, changes around the upper lip can affect the lower endpoint or make the interval appear longer. Sforza and colleagues documented age-related changes in visible lip height. Nunes and Bran found that removing philtral definition made the skin above the lip look longer in edited portraits, even without lengthening it.