The condition is considered to be vitreous opacity when the eye sees black dots, or black floaters, which are usually more noticeable when looking at a bright background or a white wall. It is similar to flying mosquitoes in front of the eyes, so it is also known as mosquito flying disease. Flying mosquitoes is mainly due to ageing, or myopia and the deepening of the vitreous degeneration, resulting in vitreous opacity phenomenon. In the clinic is mainly to observe, and there is no good way to treat, consider is a physiological changes, so that there is no need to use methods to treat. However, if there is a sensation of lightning in front of the eyes, or a large black shadow covering the visual field, it is necessary to go to the hospital to check whether there is a fissure or degeneration in the peripheral retina. If there is a fissure, laser treatment is also needed in time.