ICD-10 Code H57.052 – Tonic pupil, left eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H57.052 – Tonic pupil, left eye
What it is
H57.052 identifies a tonic pupil affecting the left eye. This means the pupil reacts abnormally to light and may constrict slowly or unevenly.
Clinical signs
Typical findings include anisocoria, a sluggish or segmental pupillary response, and better constriction to near effort than to light. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents tonic pupil, Adie pupil, or a tonic pupillary disorder limited to the left eye. Code it when the diagnosis is established in the note, exam, or assessment. Check documentation if the laterality is unclear or if the finding is only suspected.
Do not use for
Do not use this code for generalized anisocoria without a diagnosed tonic pupil. Also avoid it when the record describes another cause of abnormal pupil size or reactivity. Check documentation.
Coding tip
Confirm laterality and the exact diagnosis term in the provider note before assigning H57.052.