Cloudy material in the clear vitreous of the human eye can be manifested as mosquito flying, clinically known as vitreous turbidity. Vitreous turbidity can be divided into two categories: physiological vitreous turbidity and pathological turbidity, part of which can be absorbed through metabolism itself, but the cause of vitreous turbidity will not completely disappear. 1, vitreous turbidity is divided into two categories: physiological vitreous turbidity: often due to congenital or age factors that lead to changes in vitreous metabolism, resulting in metabolized cells or metabolites floating in the vitreous, this type of vitreous turbidity usually has little impact on vision and life, patients complain of small black shadows floating in front of the eyes, no significant change over time, may be due to change position to outside the line of sight or metabolic absorption and symptoms disappears, such cases can not be dealt with, but if the number of small floating black shadows in front of the eyes suddenly increased, or a feeling of flashing in front of the eyes, or a fixed black shadow obscured, should promptly go to the hospital. 2, pathological vitreous clouding: this kind of vitreous clouding caused by inflammation or hemorrhage, manifested as floating black shadows in front of the eyes, such as filiform, dotted, block, can gradually diffuse into a piece. If it is caused by hemorrhage, such as diabetic retinopathy stage IV, retinal vein obstruction, retinal fissure, intraocular tumor hemorrhage, etc., first of all, the cause should be identified, such as diabetic retinopathy stage IV or retinal vein obstruction, some people can absorb it by themselves through the eye’s metabolism, and can be assisted by taking drugs to promote blood circulation and remove blood stasis. If the blockage is not absorbed for 3 months, or if there is no improvement for 1 month, surgery is needed to remove the cloudy vitreous, otherwise the blood inside the vitreous may be mechanized to form a fibrous membrane and pull the retina, causing retinal detachment. If it is caused by inflammation, such as endophthalmitis, uveitis, retinitis, inflammatory cells in the vitreous body into a mass causing the floating black shadow in front of the eyes, should be clearly diagnosed and promptly anti-inflammatory treatment. Symptoms of keratitis and treatment. Most of the flying mosquitoes in life for the physiological vitreous clouding, caused by changes in vitreous metabolism, can not be dealt with, but if other causes of flying mosquitoes, should promptly seek medical care, drug or surgical treatment.