With the dry weather in northern spring, eyes are also prone to dryness, and many friends suspect they have dry eyes. However, dry eyes are not the same as dry eyes. I will explain it to you in detail below. Dry eyes are an eye symptom with many different causes. And dry eye as a disease, also called conjunctival dryness, belongs to a chronic syndrome. The main symptoms are dry eyes, foreign body sensation, eye redness, itching or feeling painful. Dry eyes are not considered to be dry eyes if they are dry for a short period of time and can be improved after care. At present, there is no unified standard for dry eye diagnosis internationally, and the colleagues of keratoconus group have proposed the diagnostic criteria for dry eye in China: 1. Dry eye can be diagnosed by having one of the subjective symptoms such as dryness, foreign body sensation, burning sensation, fatigue, discomfort, fluctuation of vision and BUT ≤ 5s or SchirmerI test (without surface anesthesia) ≤ 5ram/5rain; 2. fatigue, discomfort, fluctuating visual acuity and one of the subjective symptoms such as 5S