# Lateral Canthal Tilt

Harmony · Front view · Eyes · https://www.faceiqlabs.com/support/harmony/lateral-canthal-tilt

The upward or downward slope from the inner eye corner to the outer eye corner.

## What is measured

Calculation: Mean signed angle of the inner-to-outer canthus line against horizontal

## Why it matters

The line connecting the eye corners contributes to the eye area’s orientation. It is independent of how much upper lid is visible and should be read alongside eye shape rather than alone.

- Negative: the outer corner is lower than the inner corner.
- Positive: the outer corner is higher; zero is level.

## Where the idea comes from

Evidence: FaceIQ adaptation. Canthal orientation is an anatomical description of the eyelid opening. FaceIQ turns a photographic angle into a score; the population reference is background, not validation of a specific tilt target.

## A worked example

An outer corner 3 units higher over a 30-unit horizontal run gives arctan(3 ÷ 30), approximately 5.7°.

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

## How to read your result

A tilted head rotates both eye lines. Mark the actual corners, not eyeliner, lashes or the hood beyond the eye.

## 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. (2005). [International anthropometric study of facial morphology in various ethnic groups/races](https://pubmed.ncbi.nlm.nih.gov/16077306/). Documents variation in facial dimensions across sampled populations. Descriptive measurements explain variation; they do not establish an attractiveness score.

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Source: https://www.faceiqlabs.com/support/harmony/lateral-canthal-tilt · FaceIQ Labs overview for AI assistants: https://www.faceiqlabs.com/llms.txt