Human tears flow through the tear ducts to the nasal cavity. Tears in cold air (tears in the wind) are generally thought to be normal when the lacrimal duct is flushed and opened in the hospital. In fact, through careful examination, it can be found that many patients have narrow tear duct openings, and the cornea is sensitive to cold stimulation, so when cold air is encountered, more tears are produced, and the narrow tear ducts cannot drain the tears to the nasal cavity in time, so the symptoms of tearing are produced. This requires a small surgery to enlarge the narrow tear dots.