Night blindness is a condition in which people have difficulty seeing in dimly lit environments or at night or cannot see at all and have difficulty moving around. According to its etiology, it is divided into temporary night blindness, acquired night blindness, congenital night blindness, etc. However, most of them are temporary night blindness caused by vitamin A deficiency. A clear diagnosis can be made based on the medical history, combined with clinical symptoms and relevant examinations. I. Judgment of night blindness 1. Judgment according to medical history Ask whether there is any previous history of vitamin A deficiency or certain digestive system diseases; whether there is diffuse choroiditis, extensive choroidal ischemic atrophy and other diseases; whether there is congenital genetic eye disease, such as retinitis pigmentosa. If the above conditions are present, temporary night blindness, acquired night blindness, congenital night blindness can be initially considered in order. 2. Judgment according to clinical performance Normal vision in daytime or in good light, but poor vision at night or in low light, accompanied by other symptoms, such as reduced tears, frequent blinking, dry eyes, eye pain, reduced visual field, etc. 3. Judgment according to auxiliary examination Dark room test, plasma vitamin A measurement, visual field examination, fundus examination, etc., if necessary, be given experimental treatment, if the test results are abnormal, or through experimental treatment night blindness is significantly relieved, can be judged as night blindness. Second, the treatment of night blindness Once diagnosed with night blindness, the corresponding treatment should be carried out according to the cause, as follows: 1, temporary night blindness: supplementation of vitamin A, more pig liver, carrots, cod liver oil, etc., but vitamin A supplementation must be carried out under the guidance of a doctor, overdose can cause poisoning; 2, acquired night blindness: can be for diffuse choroiditis, extensive choroidal ischemic atrophy and other diseases Treatment; 3, congenital night blindness: night blindness symptoms can appear after birth, does not worsen with age, and there is no specific treatment.