There are streaks in the eye, especially black ones, which are more obvious when looking at a bright background or a white wall, this condition is usually considered vitreous opacity, which is often referred to as the phenomenon of flying mosquitoes, usually due to age or myopia deepening caused by vitreous degeneration, opaque phenomenon. But it is a physiological change, the clinical is mainly to observe, do not take any therapeutic intervention, and there is no good way to treat vitreous clouding, usually clinical observation. However, if there is a flashing sensation or a large dark shadow covering the eye, it is necessary to promptly go to the hospital for a review to exclude the fissure and degeneration of the fundus, and once there is such a problem, laser treatment may also be required to do so.