The common symptom of posterior vitreous detachment is a flashing sensation in front of the eyes, with spider web-like dark shadows floating around, which can cause complications such as vitreous blood accumulation, retinal fissure, retinal detachment and macular anterior membrane. The simple posterior vitreous detachment does not require treatment, but patients need to be treated if complications occur. The common cause of posterior vitreous detachment is the liquefaction of the vitreous with age. In addition to age, other factors such as aphakic eye, endophthalmitis, vitreous blood accumulation, and long eye axis can also cause posterior vitreous detachment, which refers to the separation of the vitreous from the inner boundary membrane of the retina.