If there are small black dots flying when you close your eyes, you are usually considered to have Flying Mosquito Disease (FMD), which is also known as physiologic vitreous clouding, mainly due to myopia aggravation or ageing, which is caused by the phenomenon of vitreous degeneration and opacification. This condition is very common among middle-aged and old people or high myopia, and there is a tendency to advance in age. Clinically, this condition is mainly observed, as it is a normal physiological change, so there is no need to take any intervention, and there is no good way to intervene in the mosquitoitis, mainly observation and follow-up. This phenomenon is easy to appear when the eyes are closed or bright background, mainly to their own adaptation, do not often look for it, slowly adapt, this symptom will be reduced.