A 62-year-old man underwent an uneventful cataract surgery in the left eye following retrobulbar anesthesia. Fifteen minutes after the surgery, the patient had visual loss in his right (unoperated) eye, headache, dizziness, nausea, and vomiting. The bandage on the left (operated) eye was removed and the initial ophthalmic examination revealed bilateral dilated pupils with absence of light perception. His fundus examination and vital signs were unremarkable. Immediately, a computerized tomography (CT) was performed to scan both orbit and brain. The orbit CT revealed air bubbles within the left optic nerve sheath, which confirmed inadvertent injection and administration of anesthetic medications into the optic nerve sheath. Within three hours, meningeal irritation signs recovered spontaneously and visual acuity improved to 20/20 in the right eye and 20/40 in the left eye.