Dark haze, also known as blackness before the eyes, may be related to hypoglycemia, anemia, postural hypotension and other diseases. 1. Hypoglycemia: If patients with diabetes have poor blood sugar control or overdose of hypoglycemic drugs, hypoglycemia will easily occur, resulting in darkness, blurring, weakness and other symptoms. 2. Anemia: when long-term diet irregularities, picky eaters or insufficient nutritional intake, etc., will easily lead to the phenomenon of anemia. If anemia is more serious, it will cause a decrease in the amount of red blood cells in the blood, resulting in a decrease in the oxygen-carrying capacity of the blood, resulting in symptoms such as darkness before the eyes, pallor, and weakness. 3. Postural hypotension: When there is a sudden and drastic change in body position, such as getting up suddenly from a squatting position or sitting up suddenly from a lying position, it will easily lead to postural hypotension and transient darkness in front of the eyes. In the case of black haze, you should go to the hospital in time, clarify the cause of the disease and then follow the doctor’s instructions for treatment.