Dark circles floating in the eyes 4 years after retinal detachment surgery are usually caused by vitreous clouding or residual silicone oil droplets in the vitreous cavity. Four years after the retinal detachment surgery, the patient still has a black circle floating in the eye, the most likely cause is due to vitreous clouding, because with the age or eye disease stimulation, the vitreous cavity may have turbidity formation, at this time the patient will be in the field of vision when looking at things, there is a black circle floating. If the patient had vitrectomy surgery and silicone oil was injected into the eye to promote retinal reset, the silicone oil usually needs to be removed about 3 to 6 months after the surgery. However, there may be a small amount of silicone oil droplets left in the vitreous cavity, and the patient may feel that there is a black circle when he/she looks at something. Retinal detachment surgery 4 years after the eyes have black circles floating may also be due to other reasons, it is recommended that patients go to the regular hospital ophthalmology examination, by the doctor to confirm the diagnosis, according to the condition, the use of targeted treatment programs.