Blackout: Understanding transient vision loss

BACKGROUND: Transient vision loss may indicate underlying disease of the eye, optic nerve, orbit, brain or heart. Detailed history-taking followed by a complete ocular and neurological examination is therefore a crucial part of any consultation. OBJECTIVE: It is important to determine whether a patient with transient vision loss can be reassured or requires urgent referral for further investigation. This review examines monocular and binocular transient vision loss and provides a structured approach to the examination of a patient with transient vision loss. The aim of this article is to provide clinicians with confidence when encountering these patients. DISCUSSION: Transient vision loss can imply serious underlying pathology; therefore, accurate history-taking and astute observation are paramount. This review discusses the differential diagnosis of monocular and binocular transient vision loss and the relevant localising features of each.