BACKGROUND Sudden vision loss usually requires urgent ophthalmic assessment. Diagnosis and management requires the judicious use of a wide range of serological and imaging investigations to guide appropriate treatment and referral. OBJECTIVE This article follows on from the previous discussion of the role of history and examination to discuss the appropriate investigation and management of common causes of sudden visual loss. DISCUSSION The key historical and examination findings have now been extracted and synthesised and these inform the next step. The general practitioner must now decide upon the most appropriate and timely investigation pathway or the need for, and urgency of, referral.Lucy Goold, Shane Durkin, John Crompto