Eye opening is an important clinical sign of wakefulness, which is likely mediated by a combination of midbrain and cortical mechanisms1. It forms a central part of assessments such as the Glasgow Coma Scale. However, periods of eye opening can also be seen in pathological states, such as epileptic seizures (e.g. axial tonic seizures or eyelid myoclonia), where they are not reflective of an awake state2. Here we describe a case of periodic eye opening in an unusual electroclinical context: a patient with hypoxic-ischaemic encephalopathy secondary to cardiac arrest and with a burst suppression pattern on EEG where bursts are timelocked to periods of eye opening. We present and discuss the case, characterise the electroclinical features in the context of existing literature3,4, and review the underlying anatomy and physiology. Finally, we discuss the importance of recognising and understanding this rare but striking clinical sign, both for clinicians and for patients’ relatives.