# One Eye Apart Test

Harmony · Front view · Eyes · https://www.faceiqlabs.com/support/harmony/one-eye-apart-test

The gap between the inner eye corners compared with the average eye-region width.

## What is measured

Calculation: Inner-corner gap ÷ average inner-corner-to-outer-hood span

## Why it matters

This provides a local spacing comparison. Unlike Eye Separation Ratio, it compares the eye gap with the eyes themselves instead of the whole face width.

- Below 1: the gap is smaller than the reference eye width.
- Above 1: the gap is larger than the reference eye width.

## Where the idea comes from

Evidence: Classical proportion. The one-eye-width gap is a classical facial canon. FaceIQ uses the outer eyelid-hood endpoints in its denominator, which may differ from a study’s outer canthus landmarks.

## A worked example

A 30-unit inner-eye gap and 30-unit average eye span give 1.0. A 33-unit gap with the same span gives 1.1.

Example values explain the calculation. They are not a target range.

## How to read your result

Do not use pupils for the gap. Eyelid-hood endpoints and the true outer eye corners are different landmarks.

## Research & further reading

These sources explain the history or related evidence. FaceIQ’s score weights and reference ranges are model settings; the papers do not collectively validate the scoring system.

- Farkas et al. (1985). [Vertical and horizontal proportions of the face: revision of neoclassical canons](https://pubmed.ncbi.nlm.nih.gov/3883374/). Tested nine traditional proportion rules against measured faces. Useful history for facial thirds and width comparisons; classical rules are not universal targets.

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Source: https://www.faceiqlabs.com/support/harmony/one-eye-apart-test · FaceIQ Labs overview for AI assistants: https://www.faceiqlabs.com/llms.txt