ICD-10 Code H57.059 – Tonic pupil, unspecified eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H57.059 – Tonic pupil, unspecified eye
What it is
This code identifies a tonic pupil in an unspecified eye, meaning one pupil reacts abnormally slowly to light and near focus. Use it when the chart documents a tonic or Adie-type pupil but does not specify right or left.
Clinical signs
Typical findings include a dilated pupil with poor light response and a better near response than expected. Clinical features vary; refer to documentation for the affected eye and any associated neurologic findings.
When to use this code
Use H57.059 when the provider documents tonic pupil and the record does not identify the eye. It also fits follow-up visits for a known tonic pupil when the laterality remains unspecified. Confirm that the note supports the diagnosis, not just anisocoria.
Do not use for
Do not use this code for other pupil abnormalities, such as fixed dilated pupil, unless tonic pupil is documented. If the affected eye is named, choose the laterality-specific code instead. Check documentation.
Coding tip
Query for laterality when the record says tonic pupil but does not state right or left.