There are black floaters in front of the eyes, involving many diseases of ophthalmology, mainly in the following cases: 1, the black floaters in front of the eyes are particularly small, like hair or mosquitoes, called mosquitoes, also known as vitreous opacities. This situation is mostly combined with high myopia or degenerative changes in the vitreous occurring in elderly patients, do not need to intervene, and do not need to give too much attention; 2, black floaters are larger and more fixed, such as larger than a fly, or fixed to a certain quadrant, this situation should be highly suspected of retinal hemorrhage or retinal detachment. Retinal hemorrhage may not only be a black floater, but the patient may have a red curtain in front of his eyes, and it will also be accompanied by a very obvious loss of vision, which needs to be corrected in time at an eye hospital. 3. There is another very rare and tragic situation, namely, ocular tumors, which can also have secondary retinal detachment, exudative retinal detachment or retinal hemorrhage after the occurrence of ocular tumors, and the patient needs to go to an eye hospital Patients need to go to an ophthalmology hospital for dilated pupils, detailed fundus examination, and if necessary, auxiliary examinations such as fluoroscopy or OCT for differential diagnosis of tumors.