Vitreous clouding is a common clinical condition in which large black shadows float in front of the eyes. If there is no vision loss, it is often physiologic vitreous clouding. If accompanied by vision loss, often belong to the pathologic vitreous clouding, cloudy material is mostly hemorrhage or inflammatory cells. Physiological vitreous clouding is a normal physiological change, due to old age, high myopia and other reasons lead to vitreous body gradually liquefaction, degeneration, appear in front of the eye black shadow floating. Pathological vitreous clouding is commonly caused by inflammation of the uvea, retinal hemorrhage, tumor dissemination, retinal tear or detachment and other ophthalmic diseases, and most of them will have different degrees of vision loss. It is recommended that the patient should consult a doctor in time, and the cause should be clarified according to the examination.