Fundus cracks may be caused by retinal cracks, high myopia, macular cracks and so on. 1. Retinal cracks: Retinal cracks may be caused by retinal degeneration, vitreous degeneration, posterior vitreous detachment and other factors. The patients will be found to have retinal tears during fundus examination. In addition, the patients will also have symptoms such as mosquitoes and persistent flashing sensation. 2. High myopia: High myopia may be caused by heredity, long time looking at electronic products and other factors. Patients will have decreased visual acuity, visual fatigue and other manifestations. Some patients will find funduscopic cracks when they undergo funduscopic examination. 3. Macular tear: Macular tear may be caused by trauma, ocular inflammation, erosive retinopathy and so on. Patients will find the fundus cracks during fundus examination, and patients will also have blurred vision, distorted vision and other symptoms. It is recommended that patients with fundus opacification need to consult a doctor in time, and the doctor will choose the appropriate measures for the cause of the disease. Patients should get enough sleep and avoid playing with cell phones or looking at computers for a long time.