Doctors in Mexico didn’t miss a beat when it came to diagnosing this patient’s pulsating pupils.

The 73-year-old man with a history of hypertension initially presented to an ED complaining of shortness of breath.

Doctors noted a high blood pressure, and heart and respiratory rate, as well as a crescendo–decrescendo systolic murmur and a decrescendo diastolic murmur. But it was the ophthalmic examination that revealed a truly unusual sight.

Captured on video, the patient’s pupils could be seen contracting and dilating in time with his heartbeat.