Changes in vision or loss of vision are common complaints for patients presenting to the emergency department. Such complaints may represent a simple problem related to recent trauma, early evidence of a systemic disease, or may be a vision-threatening lesion. A logical and organized approach to the history and the physical examination of the patient with eye complaints is key to the diagnosis and treatment of the more significant causes of these complaints. This article reviews an organized approach to the patient with complaint of visual loss and considers the wide differential diagnosis. It focuses specifically on the evaluation of the patient complaining of visual changes resulting from central retinal artery occlusion, central retinal vein occlusion, retinal detachment, acute angle-closure glaucoma, giant cell temporal arteritis, and retrobulbar hemorrhage.