**Data source**
Spinal segment data is compiled directly into the app (no external asset file is loaded at runtime). The zone-to-segment mapping follows the **pupillary-border iridology convention**:
| Iris clock position | Spinal region |
|——————–|—————|
| 12 o’clock (upper-central) | Upper Cervical C1–C4 |
| 10–11 / 1–2 o’clock (upper) | Mid/Lower Cervical C4–C7 |
| 9 / 3 o’clock (middle) | Upper Thoracic T1–T6 |
| 7–8 / 4–5 o’clock (lower) | Lower Thoracic T7–T12 |
| 6 o’clock (lower-basal) | Lumbar / Sacral L1–S3 |
Both eyes map to the **same spinal column** — the spine is midline, so OD and OS findings at the same clock position point to the same vertebral level.
**What the panel shows**
Each spinal segment card displays:
| Section | Contents |
|———|———|
| **Segment label** | e.g. “Upper Cervical C1–C4” |
| **Vertebrae** | Individual vertebrae with common names (e.g. C1 Atlas, C2 Axis) |
| **Nerve roots** | Exiting nerve roots at that level |
| **Innervated structures** | Organs and tissues supplied by those nerves |
| **Subluxation indicators** | Classic symptoms associated with fixation at this level |
| **Affected muscles** | Muscles commonly involved in nerve compromise at this level |
| **Adjusting approach** | Standard chiropractic techniques applicable to the region |
| **Exercises** | Corrective exercises, stretches, and lifestyle recommendations |
| **Postural note** | Ergonomic or postural guidance specific to this spinal region |
**Sources**
Winsor (1921) sympathetic segmental disturbances study; Cleveland Chiropractic College nerve–organ chart; Palmer textbooks; Jensen and Angerer iridology references.
