Red blood next to the pupil of the eye, may be due to the iris neovascularization, may also be due to ocular inflammation, acute glaucoma and other causes. 1. Iris neovascularization: iris neovascularization, usually caused by ischemic fundus diseases, such as ocular ischemia syndrome, central retinal artery obstruction, diabetic retinopathy, etc., can lead to the release of neovascular factors, and then the formation of neovascularization, which can be manifested in the eye pupil next to the red blood. 2. Ocular inflammation: common in keratitis, uveitis, under the stimulation of inflammation, can lead to the pupil of the eye next to the red blood, may also be accompanied by eye itching, eye pain and other symptoms. 3. Acute glaucoma: red blood next to the pupil of the eye, if accompanied by increased intraocular pressure, pupil dilatation, corneal edema and other symptoms, you should be alert to the possibility of acute glaucoma attack triggered. Red blood next to the pupil of the eye, may also be related to other factors, if the symptoms continue to be unable to alleviate, or there are other symptoms of discomfort, you should seek medical attention as soon as possible, after diagnosis of the cause of the doctor’s guidance for treatment.