Manual
Ocular motility & alignment
The Eye Exam
Ocular motility & alignment
H-pattern, cover tests and Hirschberg.
- 1Hirschberg: corneal light reflex — 1 mm decentration ≈ 7° (≈ 15 Δ).
- 2Ductions/versions in the 9 cardinal positions (H pattern + up/down).
- 3Cover–uncover test: movement of the uncovered eye = tropia.
- 4Alternate cover test: reveals total deviation (phoria + tropia); neutralise with prisms.
- 5Saccades, pursuit, convergence; look for nystagmus.
| Muscle | Primary action | Innervation |
|---|---|---|
| MR | Adduction | CN III |
| LR | Abduction | CN VI |
| SR | Elevation (abducted) | CN III superior div. |
| IR | Depression (abducted) | CN III inferior div. |
| SO | Intorsion, depression (adducted) | CN IV |
| IO | Extorsion, elevation (adducted) | CN III inferior div. |
Mnemonic: LR6 SO4 — all others CN III. The obliques act opposite to their names in vertical gaze when the eye is adducted.
Educational summary — follow local protocols and current guidelines.