Insights · Eyes · Measurement

Interpupillary distance : face width (Pallett)

Pallett, Link & Lee (2010): raters preferred an interocular distance of ≈0.46 of face width.

Confidence
Tier B · wide interval
Unit
ratio (dimensionless)
Landmarks
iris_R, iris_L, zy_R, zy_L
CI floor
± 0.02
dist(iris_R, iris_L) / dist(zy_R, zy_L)
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Illustration · on your scan the same lines are drawn on your own photo

How to read it

Below the mean

the pupils are close together relative to face width.

Near the mean

this proportion sits near the value Pallett et al. identified as preferred/average.

Above the mean

the pupils are widely spaced relative to face width.

Reference values by population

Reference populationFemale (mean ± SD)Male (mean ± SD)nSource
North American White0.46 ± 0.030.46 ± 0.03Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov.
East Asian0.46 ± 0.030.46 ± 0.03Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov.
South Asian0.46 ± 0.030.46 ± 0.03Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov.
African / African diaspora0.46 ± 0.030.46 ± 0.03Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov.
Middle Eastern0.46 ± 0.030.46 ± 0.03Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov.
Hispanic / Latino0.46 ± 0.030.46 ± 0.03Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov.
Not specified — show pooled0.46 ± 0.030.46 ± 0.03Pallett et al. 2010 — Caucasian female faces. Provisional for other groups. prov.
Where these numbers come from

Transcribed from the cited anthropometric literature; SDs of ratios are propagated conservatively (independence assumed). Entries marked prov. await line-by-line audit against the primary tables — see the norm provenance note.

Why every value has an error bar

Every value Canthion reports carries a 1σ uncertainty propagated from MediaPipe Face Mesh's published accuracy (3.96% of inter-ocular distance mean absolute error per landmark, Kartynnik 2019). For a typical 300 px inter-pupil photo that is ≈12 px per landmark, which is why small ratios and angles get wide intervals. A number without an interval is a number pretending to be more precise than it is.

References

Related: how bone-level measurements are taken from a photo · methodology · all insights