ral anticoagulation medications, such as aspirin, clopidogrel bisulfate, and warfarin sodium, have been associated with the development of vitreous hemorrhage. 1,2 While many cases of vitreous hemorrhage may resolve spontaneously, nonclearing vitreous hemorrhage may result in significant visual morbidity and require surgical intervention.Rivaroxaban is an oral anticoagulant increasingly used in the management of atrial fibrillation. It is an oral factor Xa inhibitor administered in a single daily dose. The use of rivaroxaban has been associated with hemorrhagic complications 3,4 involving the gastrointestinal, intracranial, and urinary systems. Other factor Xa inhibitors include fondaparinux, apixaban, and edoxaban.We demonstrate an association between rivaroxaban use and spontaneous vitreous hemorrhage. The risk may be particularly serious during the transition period, when more than 1 anticoagulant could be prescribed. Report of Cases Case 1A man in his mid-70s with a medical history of atrial fibrillation was evaluated for an acute vitreous hemorrhage of his right eye. The patient was in the process of transitioning his atrial fibrillation anticoagulation regimen from warfarin to rivaroxaban. His international normalized ratio was therapeutic. His ocular history was remarkable for a retinal