Ms. Li is 37 years old and highly myopic. One day she noticed dark shadows floating in front of her eyes, and when she looked at bright places, white walls and blue skies, there were mosquitoes and thread-like things fluttering in front of her eyes and moving together with her vision. The doctor told her that she had a retinal fissure, but due to timely treatment, it did not detach, so she was immediately given laser treatment to “repair” her retinal fissure. The laser treatment took only 5 minutes and cost a few hundred dollars to fix the disease and her vision was not affected. The doctor told her that if she did not seek medical attention in time, the retina would detach, and then surgery would cost a lot of money in addition to the prognosis would be very poor. Ms. Li is secretly glad that she escaped a disaster by seeking medical attention in time! The black floating shadow in front of the eye is mainly due to intraocular vitreous liquefaction, cloudiness or bleeding caused by the vitreous cavity of the cloudy material blocking a small part of the vision, the formation of a “flying mosquito” in front of the eyes. When the eye movement, the intravitreal clouding also occurs movement, so the formation of the “flying mosquito” in front of the eyes. There are 70% of the vitreous turbid medical called “physiological flying mosquitoes”, although the mosquitoes in front of the eyes flying very annoying, but no impact on vision. In addition, there are 30% of the black shadow floating in front of the eyes, is caused by disease, mainly intraocular hemorrhage, inflammation and other diseases caused by. The main and most serious diseases are retinal fissure formation and retinal detachment occurring. The dark fluttering and flashing sensation in front of the eye indicates the pulling of the retina by the vitreous body, and in the process, it is likely to form retinal fissures, which, if not treated in time at an early stage, will most likely develop into retinal detachment, leading to severe vision loss and blindness if not treated in time. The high prevalence of black shadows in front of the eyes is mainly in middle-aged and elderly people, highly myopic eyes and diabetic people. The above-mentioned people, such as the sudden emergence of black fluttering in front of the eyes, should promptly seek medical attention, detailed examination of the fundus, including dilated pupils after examination of the fundus, ocular ultrasound examination. If it is “physiological flying mosquitoes”, then appropriate use of oral medication or Chinese herbal remedies, usually pay attention to proper rest, avoid strain, to work, rest to be regular, long time eye rest every hour for 5 to 10 minutes, do not use the computer for too long, eat more food containing vitamin C, such as vegetables and fruits. If a retinal fissure is formed, then laser treatment should be scrambled to avoid the development of retinal detachment that can lead to blindness.