---
title: 3.4 ANW Assessment (Collarette / Autonomic Nerve Wreath)
description: "****What the ANW is**** The ANW (Autonomic Nerve Wreath), also called the collarette, is a textured ring visible in the iris approximately one-third of the way between the pupil and the iris rim. It marks the transition between the inner…"
url: "https://cnri.edu/docs/3-4-anw-assessment-collarette-autonomic-nerve-wreath/"
updated: "2026-03-24"
category: Reading the Analysis Results
---

# 3.4 ANW Assessment (Collarette / Autonomic Nerve Wreath)

****What the ANW is****

The ANW (Autonomic Nerve Wreath), also called the collarette, is a textured ring visible in the iris approximately one-third of the way between the pupil and the iris rim. It marks the transition between the inner and outer iris zones and reflects autonomic nervous system tone.

****ANW Ratio****

The ratio measures the ANW ring diameter relative to the iris diameter.

| ANW Ratio | Status | Autonomic interpretation |

|-----------|--------|-------------------------|

| < 25% | ****Spastic**** | ANW ring contracted inward — sympathetic dominance, hypertonicity |

| 25–35% | ****Normal**** | Balanced autonomic tone |

| > 35% | ****Atonic**** | ANW ring expanded outward — parasympathetic dominance, hypotonicity |

****ANW Asymmetry****

The asymmetry between OD and OS ANW ratios is also measured. An asymmetry of ****0–5%**** is normal. A larger asymmetry, particularly where one eye is Spastic and the other is Atonic, is flagged as a ****Functional Frustration**** pattern.

****ANW Shifts****

Local sectors of the ANW ring that deviate inward or outward from their expected position by more than ****8%**** are reported as ANW Shift findings (badge: ****ANW****). Like FLAT/PROT findings, each shift is mapped to a clock zone and assigned its historical organ association.

****Bilateral comparison****

After both eyes are analysed, the bilateral ANW summary compares OD and OS ratios side-by-side, calculates the asymmetry, and flags the functional frustration pattern if present.