Blackness in front of the eyes can not see, there are several possibilities: a. If it is a transient black haze, it may be caused by spasm of the central retinal artery, or ophthalmic artery, related to hypertension, diabetes, atherosclerosis, etc. It is necessary to treat the original disease and take oral vasodilator drugs. Second, sudden black blindness in front of the eyes is due to blockage of the central retinal artery, or ophthalmic artery. The most common cause is atherosclerotic plaque in the neck vessels, and the embolus is dislodged, blocking the central retinal artery or ophthalmic artery. This condition must be treated urgently by giving retrobulbar injection of atropine, sublingual nitroglycerin, oxygen, intravenous vasodilator drugs, and oral vinpocetine tablets to lower intraocular pressure. If the obstruction is relieved within one hour after the onset of the disease and after treatment, it is possible to restore some of the vision, and it is difficult to restore vision after a long onset of the disease. Third, vitreous hemorrhage, common in diabetic patients, need to control blood sugar, oral calcium hydroxybenzene sulfonate to promote the absorption of bleeding. If the blood accumulation in the vitreous does not absorb for a month, vitrectomy is needed.