Acute vision loss is the temporary reduction of visual acuity or visual field, lasting from a few minutes to a few days. The etiologies of acute vision loss may be divided into anterior segment disease, retinal disease, optic nerve disease, or neurovascular disease. It is recommended to refer all presentations of acute vision loss for ophthalmologic consultation; however, the primary care physician plays an important role in determining the urgency of referral. The following article describes an approach to narrowing the differential diagnosis of acute vision loss, using relevant ocular history and physical exam findings. The features of common eye disorders relating to acute vision loss and their treatments are also discussed.