With the current tendency of increasing minimally invasive cosmetic surgeries, some rare but disastrous complications of facial filler injections come into sight, such as visual loss. The study aims to investigate the possible route that the injected droplet accesses the ophthalmic artery to explain and prevent such devastating complications. We searched the National Library of Medicine's PubMed database for cases of visual loss secondary to cosmetic facial filler injection, and reviewed relevant case reports/surveys, as well as accompanying references. Data obtained were analyzed, with special interest in injected sites and filler material, and clinical features of visual loss. Based on the anatomy of facial vessels, we inferred the possible route of injected droplet migrating from injection sites to ophthalmic artery. Most physicians propose a retrograde embolic mechanism, but the culprit artery when injecting different sites is not determined. We consider accidentally breaking into supraorbital artery or supratrochlear artery may cause occlusion of ophthalmic artery when injecting into glabella or forehead region. Speaking of the nasolabial fold and nasal dorsum region, any injections in the anastomosis of the dorsal nasal artery, angular artery, and lateral nasal artery can lead to retrograde embolism. Similarly, in the temporal region, we believe there is abnormal anastomosis between frontal branch of superficial temporal artery from external carotid artery and supraorbital artery from ophthalmic artery. In our hypothesis, we can explain the accompanying brain infarction after iatrogenic visual loss. If the injecting pressure is forceful enough, it may push the embolic materials into middle cerebral artery. Although iatrogenic ophthalmic artery occlusion is a rare complication after the facial filler injection surgery, it is usually devastating. Both the patient and the surgeon should be aware of the risk of irreversible blindness. Ideally, the injection sites should avoid the small vessels nearby, the injecting force and velocity should be as gentle and slow as possible.