Whether or not a dark shadow drifting in the eye is a case of Aedes aegypti also depends on whether it is a fixed dark shadow, or a movable or sporadic dark shadow. If it is a fixed black shadow may not be the case of flying mosquito, but the visual field defect, this situation is common in intraocular hemorrhage or retinal detachment, and retinal detachment is more common, often due to the retina of the retinal hole, or degeneration and lead to retinal detachment phenomenon. If the detachment is small, it can be treated with laser, while large-scale detachment can only be solved by surgery. If it is intermittent black shadow fluttering, sometimes is the phenomenon of flying mosquito, due to age or myopia deepening, and lead to the phenomenon of vitreous opacity, similar to the flying mosquito floating so also known as flying mosquito. It is a physiological change, the clinical mainly to observe the main, and does not take any treatment means, there is no good way to treat the mosquito.