Some patients come to the clinic with the complaint that there is something opaque floating in front of their eyes, which can move with the rotation of the eye, which is often referred to as mosquito flying. The floating object in front of the eye can be dotted, flying shadow, or ring shape. Mainly due to the opaque components of the concentrated gel in the visual field, in the retina projection caused by the elderly or patients with refractive error. It increases significantly in cases of eye fatigue or overuse of the eyes and is relieved significantly with rest. There are no very effective medications for vitreous opacities. The commonly used drugs are Volitene and Piven, but their efficacy is inaccurate. In recent years there is a new type of laser therapy instrument, for part of the mosquitoes, can be achieved through the laser ablation method of certain results. If the flying mosquitoes with vision loss, must be alert enough, may be the retinal fundus problems, to the hospital in a timely manner, to avoid delay.