Brow arch position
Brow apex position
Where along the eye the eyebrow reaches its highest point, on a scale from 0 at the inner corner of the eye to 1 at the outer corner.
Also searched as brow apex, eyebrow peak position and where the brow should arch.
How to read it
the brow peaks medially (a flatter or centrally-arched brow).
the brow apex sits over the outer third of the eye, the position textbook teaching describes.
the brow peaks far laterally.
This measures brow HAIR, which is plucked, threaded, dyed, tattooed and drawn on. It is not a biological measurement and should not be read as one.
Reference values by population
| Reference population | Female (mean ± SD) | Male (mean ± SD) | n | Source |
|---|---|---|---|---|
| North American White | 0.72 ± 0.12 | 0.72 ± 0.12 | — | Textbook convention (apex over lateral limbus). No population anthropometry exists for this. Provisional. prov. |
| East Asian | 0.72 ± 0.12 | 0.72 ± 0.12 | — | Textbook convention (apex over lateral limbus). No population anthropometry exists for this. Provisional. prov. |
| South Asian | 0.72 ± 0.12 | 0.72 ± 0.12 | — | Textbook convention (apex over lateral limbus). No population anthropometry exists for this. Provisional. prov. |
| African / African diaspora | 0.72 ± 0.12 | 0.72 ± 0.12 | — | Textbook convention (apex over lateral limbus). No population anthropometry exists for this. Provisional. prov. |
| Middle Eastern | 0.72 ± 0.12 | 0.72 ± 0.12 | — | Textbook convention (apex over lateral limbus). No population anthropometry exists for this. Provisional. prov. |
| Hispanic / Latino | 0.72 ± 0.12 | 0.72 ± 0.12 | — | Textbook convention (apex over lateral limbus). No population anthropometry exists for this. Provisional. prov. |
| Not specified — show pooled | 0.72 ± 0.12 | 0.72 ± 0.12 | — | Textbook convention (apex over lateral limbus). No population anthropometry exists for this. Provisional. 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). On a typical photo with 300 px between the pupils, that is about 12 px of wander on every point. Small ratios and angles inherit it, so their intervals are wide. A number without an interval is a number pretending to be more precise than it is.
References
- Clinical norm: lateral canthus sits ~2–4 mm superior to the medial canthus (≈ +4° to +7° at ICD ≈ 30 mm). Evaluation of Eyelid Function and Aesthetics (Plastic Surgery Key, textbook chapter). plasticsurgerykey.com/evaluation-of-eyelid-function-and-aesthetics/
Common questions
What is brow arch position?
Where along the eye the eyebrow reaches its highest point, on a scale from 0 at the inner corner of the eye to 1 at the outer corner. Textbook aesthetic teaching places the apex at or lateral to the lateral limbus (~0.65–0.9).
How is brow arch position measured from a photo?
It is computed from the face-mesh landmarks (brow_R, brow_L): (apex.x − en.x) / (ex.x − en.x), averaged over both brows. Every value carries a 1σ error bar propagated from the landmark detector's published accuracy, with a floor of ± 0.06, so a small difference inside the interval is not a difference.
What is a normal brow arch position?
Across the reference populations the anatomical norm is the same: 0.72 ± 0.12 for women, 0.72 ± 0.12 for men. This value is provisional and awaits line-by-line audit against the primary tables. Your own value is placed on the distribution you choose, as a percentile with its error bar.
What does a low or high brow arch position mean?
Below the mean: the brow peaks medially (a flatter or centrally-arched brow). Above the mean: the brow peaks far laterally.
How reliable is brow arch position from a photograph?
This measures brow HAIR, which is plucked, threaded, dyed, tattooed and drawn on. It is not a biological measurement and should not be read as one.
Brow position and brow height carry the largest published sex difference of any photographic facial trait.
Related measurements
The rest of the eyes set, then the nearest measurements elsewhere on the face. Every one is computed on the same photograph, in the same run, with its own error bar.
Also: how bone-level measurements are taken from a photo · methodology · glossary · all 35 insight pages