Brow peak position: what the Carruthers ideal actually specifies

Brow position is one of the most requested changes in any med-spa consult and one of the least precisely discussed. "Arched," "flat," "heavy," and "lifted" all get used as if they described the same thing. In the aesthetic literature, brow position is a specific measurement: where the peak of the brow sits relative to the eye, not a general impression of shape.

Facet's brow module uses this specific measurement, keyed to the reference most cited on the topic, Carruthers 2020. Here is what it actually defines.

Definition

The brow peak is the highest point of the eyebrow arch. Its position is measured relative to the lateral limbus, the outer edge of the iris when looking straight ahead. Three landmarks matter for a full read:

• Peak location: where the highest point of the arch sits on the horizontal axis, ideally at or just lateral to the lateral limbus.
• Medial start point: where the brow begins near the nose, typically aligned with the alar base and the inner canthus.
• Brow-to-eye distance: the vertical gap between the brow's lower edge and the orbital rim, which reads differently by gender in the literature, closer to the rim in men, several millimeters above it in women.

Why the peak location matters more than shape

Most people describe brows by their overall shape (arched, straight, rounded). Clinically, the peak location is what drives the read, and small shifts change the face's expression at rest.

• Peak lateral to the limbus (near where the literature places the ideal): reads as alert and structured without looking surprised.
• Peak shifted medial, toward the nose: reads as a surprised or quizzical expression, even at rest.
• Low medial brow paired with a high lateral peak: reads as an angry or stern expression, independent of actual mood.
• Overelevation of the whole brow: reads as unnatural, the most common overcorrection in brow lift procedures.

This is the reason brow lift and neuromodulator injections are easy to get wrong even when the practitioner is skilled. Moving the peak medial by a few millimeters, or lifting the whole arch instead of adjusting the peak specifically, produces a face that reads as a different expression than the one the patient asked for.

What brow position does not predict

It does not predict attractiveness on its own. Brow position research measures what reads as alert, tired, surprised, or stern, not what reads as more or less attractive, and no well-powered study collapses brow position into a single desirability score. It also does not transfer cleanly across genders or ethnic groups. The male ideal sits closer to the orbital rim by design; applying a female-typical band to a male brow, or vice versa, produces a measurement that is accurate but pointed at the wrong target.

How Facet measures it

Facet's eyebrow module locates the brow peak and the lateral limbus from MediaPipe's landmark set, then measures the horizontal offset between them in millimeters, along with the medial start point and the brow-to-eye distance. Each measurement is compared against gender-typical and ethnicity-keyed bands drawn from the Carruthers 2020 aesthetic analysis of eyebrow shape and position, the same reference this module cites throughout the report.

As with every module, the point is not the single score. It is that the number behind it traces to a named paper and a specific pair of landmarks, not a general impression of whether a brow looks good.

A full example of how the eyebrow module reports this, alongside the other nine, is posted at [/sample-report](/sample-report). The citation list behind every threshold, including this one, is at [/methodology](/methodology).