Dry eye is one of the most common ocular surface diseases in the ophthalmology clinic. The most common symptoms of dry eye are dry eyes (i.e., eyes that feel dry and do not move well) and often photophobia (i.e., the feeling that you cannot open your eyes in bright light). The reason for this is that dry eyes (like a machine that lacks lubricant) make the eyeball work hard and easily damaged, and patients with dry eyes are more likely to have damage to the epithelium of the cornea and conjunctiva, causing tears when the eyes are irritated. In addition, patients with dry eyes are more likely than normal to experience visual fatigue, some with symptoms such as eye redness, decreased vision, increased discharge, visual fatigue and foreign body sensation. Common causes of dry eye include: eye surface inflammation, drugs, tumors, surgery, eye trauma and other eye pathologies; local use of cosmetics, long-term contact lens wear, excessive eye use, use of electronic products; environmental pollution, radiation, systemic diseases, congenital abnormalities, etc. Because people do not know enough about dry eye, when eye discomfort occurs but does not affect their lives much, they often go to the pharmacy to buy eye drops to spot their eyes. As a reminder, eye drops generally contain preservatives, which can damage eye surface tissues and cause pharmacogenic keratitis if improperly administered (such as long-term non-medically prescribed medication or frequent replacement of eye medication), thus aggravating the patient’s symptoms and affecting his or her life and work. Therefore, if you have symptoms of dry eyes, do not abuse eye medication, it is recommended to go to the hospital to see a professional doctor for a clear diagnosis to avoid delays in diagnosis and treatment.