Flying mosquitoes refers to a small, floating black shadow in front of the eyes, especially when looking at a bright white background, but also may be accompanied by a sense of flash. Etiology Vitreous liquefaction and posterior detachment is the main cause, 70% of patients are caused by this, but about 1/4 may have vision-threatening lesions, mainly the formation of retinal fissures. Clinical manifestations There are often flying mosquito symptoms, with small floating black shadows in front of the eyes, especially when looking at a bright white background, more obvious after careful examination did not find obvious vitreous lesions. Patients complaining of flying mosquitoes should have their pupils dilated and their fundus carefully examined. Treatment Only patients with posterior vitreous detachment do not need special treatment, for lesions that are harmful to vision, such as retinal fissures, according to the relevant treatment principles.