There are many reasons for the emergence of tears in the wind, including the problems of their own bodies, and of course, the cause of the weather. First of all, we look at the simple cause: internal Yingfengliulei mainly has two kinds, one kind is "virtual", namely the kidney two empty, as the wind tears, but not red eyes do not hurt, tears flow thin, when no heat; the other is "hot", i.e. the wind heat type, mainly for the tears of turbidity, heat, and red eyes will etc.. In fact, the external environmental factors are also the main cause of the windward tears. It is mainly reflected in the change of temperature, humidity and wind in the weather. There is a layer of lubricating film on the surface of the eyeball, that is, the tear film. In normal circumstances, the blink of an eye can smear tears evenly over the film to ensure a clear and comfortable vision. If the temperature is too low, the eyeball will be strongly stimulated by the cold wind, which will directly lead to the blockage of the lacrimal gland. Meanwhile, a lot of dust mixed in the wind will block the lacrimal gland and prevent the secretion of tears. Another reason for crying is the drying. In winter, even in the south of the Yangtze River, it will become dry relative to several other seasons, while people in the north will feel deeper about the drying in winter.