在我国现有的膳食情况下:人体维生素A的缺乏比较普遍,而缺少维生素A最容易发生夜盲、乾眼以及皮(?)干燥与毛囊角化等症状。在这些症状中,除夜盲须由患者自诉或用特殊仪器加以判定外,其他症状则均能用肉眼客观的加以诊断。发生夜盲的原因很多,但大致可分为营养性与非营养性两大类;前者以维生素A缺乏为主,後者则大多发生於患有眼底病的患者,如视神经萎缩、色素性视网膜炎、近视性视网膜(?)胳膜病变, In our country’s existing diet: the lack of vitamin A is more common in the body, and the lack of vitamin A is most prone to night blindness, dry eye and skin (?) Drying and follicular keratosis and other symptoms. In these symptoms, in addition to the night blindness by the patient’s private prosecution or by special equipment to be judged, other symptoms can be objectively diagnosed with the naked eye. Occurrence of night blindness for many reasons, but can be divided into two major categories of nutrition and non-nutrition; the former mainly vitamin A deficiency, while the latter mostly occurs in patients with fundus diseases, such as optic atrophy, retinitis pigmentosa, Myopia retina (?) Of the lesion,