One month after cataract surgery, black spots appear in the eyes, which may be caused by vitreous clouding and peripapillary retinal veinitis. 1. Vitreous clouding: before cataract surgery, the vitreous body is in a cloudy state, and it is not clear when you see external objects. After cataract surgery, due to the increase of light entering the eyes, the vitreous clouding will be obvious, which may cause the symptom of black spots in the eyes. 2. Peripapillary retinal vein inflammation: blood vessels may rupture after cataract surgery, and there may be symptoms such as dark shadows in the eyes, reddened and blurred vision after blood enters into the vitreous body, which can be treated by laser photocoagulation therapy and vitrectomy. Therefore, one month after cataract surgery with black spots in the eyes, you should go to the hospital as soon as possible to find out the cause of the disease, and actively cooperate with the doctor for treatment after diagnosis.