The opticocarotid recess (OCR) is a fixed anatomical landmark located posterolaterally in the sphenoid sinus, formed by the bony recess between the internal carotid artery (ICA) and the optic nerve. Injury at this neurovascular junction can lead to severe complications . Sphenoid sinus cysts are rare clinical entities, typically presenting with non-specific symptoms such as headache. This case report describes a patient presenting with unilateral visual deterioration. Following systematic ophthalmological and neurological examinations and multidisciplinary evaluation, initial diagnosis was challenging due to the cyst's small size, which concealed its compressive effects—effects typically expected only when the sphenoid sinus cavity is fully occupied. Progressive anatomical exploration through imaging studies ultimately localized the lesion to the OCR. Complete mucocele excision was successfully achieved via transnasal endoscopic resection, resulting in the patient's ultimate visual recovery.