The sudden appearance of dark shadows in the eyes are often seen in the following cases: 1, vitreous detachment, generally seen in the eye after impact, lifting heavy objects or strenuous exercise, generally no treatment, regular review can be; 2, vitreous clouding that is mosquitoes, mostly in highly myopic or elderly, mild mosquitoes without treatment, if you feel that the dark shadows become larger, more need to timely consultation, improve the fundus examination, serious mosquitoes can 3, mostly seen in retinal fissures, diabetic retinopathy or retinal vein obstruction, etc., it is recommended to go to the regular ophthalmology consultation, according to the condition of the fundus to take targeted treatment; 4, retinal detachment, if necessary, need to do extra-scleral pressure combined with cryosurgery or vitrectomy; 5, ischemic optic neuropathy, it is recommended to improve the visual field It is recommended to improve the visual field examination and fundus angiography, and generally need oral hormone combined with the application of microcirculation improvement and nerve nutrition drugs.