Purpose. To report patent foramen ovale (PFO) as the cause of retinal artery occlusion in a young and previously fit male and discuss the appropriate medical and surgical management options. Methods. Interventional case report with serial fundus photographs of an 18-year-old male presenting to the eye casualty with sudden onset left visual loss. Results. Visual acuities were 6/24 left and 6/4 right with a left afferent pupillary defect. Slitlamp examination confirmed a left hemiretinal artery occlusion and subsequent cardiology review with transoesophageal echocardiography revealed patent foramen ovale which was closed surgically. Conclusions. PFO is not uncommon and is often covert but predisposes individuals to embolic events. These events may be ophthalmic with visual sequelae and so ophthalmologists, physicians, and other healthcare personnel should be aware of this important and emerging association.