> For the complete documentation index, see [llms.txt](https://docs.saas.haut.ai/haut.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.saas.haut.ai/haut.ai/haut.ai-features/algorithms/face-skin-analysis-3-0/lines/crow-s-feet-lines.md).

# Crow's Feet Lines

What the Crow's Feet Lines parameter measures at the outer corners of the eyes, and how to read the grades it returns.

## About Parameter

Crow's feet develop at the delicate outer corners of the eyes where skin is thinnest. These fan-like wrinkles result primarily from the repetitive contraction of the lateral portion of the orbicularis oculi—the circular sphincter muscle responsible for squinting and smiling. While they initially appear as dynamic wrinkles that radiate outward during facial expressions, they can eventually deepen into permanent static wrinkles that remain visibly etched into the skin even when the face is completely at rest.

## Features

1. Works with frontal and side facial images, but we recommend measuring from side images since lines are more visible there
2. Evaluates overall severity (grade) of lines
3. Separates and segments deep and fine lines

## Output

1. Grade from 1 to 5.
2. Vector mask for deep lines.
3. Vector mask for fines lines.
4. Vector mask containing both deep lines and fine lines.
5. Algorithm-assigned skin condition tag (Great, Good, Average, Poor).
6. Amount of lines.
7. Amount of deep lines.
8. Amount of fine lines.
9. Length of lines relative to length of the lower eyelid curve. (in %, may exceed 100)
10. Length of deep lines relative to length of the lower eyelid curve. (in %, may exceed 100)
11. Length of fine lines relative to length of the lower eyelid curve. (in %, may exceed 100)<br>

## Grades Description

Severity assessment based on the presence and length of fine and deep lines

<table><thead><tr><th width="120.4296875">Grade value</th><th width="484.68359375">Description</th><th>Tags</th></tr></thead><tbody><tr><td>1</td><td>No visible wrinkles</td><td>Great</td></tr><tr><td>2</td><td>A small trace of fine lines, no deep lines</td><td>Good</td></tr><tr><td>3</td><td>Noticeable fine lines, no deep lines</td><td>Average</td></tr><tr><td>4</td><td>The presence of deep line length is minor, suggesting the initial stage of permanent wrinkling</td><td>Poor</td></tr><tr><td>5</td><td>Prominent, long, and deep wrinkles are clearly visible</td><td>Poor</td></tr></tbody></table>

## Algorithm API

{% hint style="warning" %}
API access is available only for <mark style="color:purple;">**Professional**</mark> plan clients
{% endhint %}

See [Crow's Feet Lines Parameter Result Scheme](/haut.ai/developers/saas-api-overview/api-for-face-skin-analysis-3.0/lines/crow-s-feet-lines.md).

***

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