The appearance of dark shadows floating in front of the eye, dotted, linear, mass-like phenomenon called mosquito flying, clinically considered to be caused by vitreous turbidity. The vitreous itself is a colorless and transparent colloid, if the vitreous itself degeneration, posterior vitreous detachment, or vitreous cavity inflammation, blood accumulation, etc., will appear in the immediate visual field of the black shadow fluttering. Therefore, when vitreous clouding occurs, the first thing to do is to go to the hospital for a routine examination, including an ultrasound of the eye and a dilated pupil to check the fundus, with the aim of clarifying the cause. If the vitreous clouding is diagnosed to be related to an eye disease, such as uveitis or retinal fissure or retinal detachment, it needs to be treated surgically. The results are not satisfactory. However, the clinical results are not very satisfactory, and in some patients the dark shadows in front of the eyes do not fade at all. If you find that the cloudy foci are obvious and cause great disturbance to your life and work, you can consider laser ablation surgery.