Dry eyes refer to the condition where the eyes are dry, lacking moisture, and feel uncomfortable and easily fatigued.

This symptom was recorded early in the Lingshu , referred to as "depletion of essence"; the "Treatise on the Origins and Symptoms of Diseases" states: "When the fluids are exhausted, dry eyes occur"; Zhengzhi Zhunsheng calls it "dryness and blurred vision"; Shenshi Yaohan has the term "white xerotic syndrome," and there are also other names such as "dry and astringent eyes."

bubble_chart Pattern Analysis

1. Yin Deficiency and Blood Deficiency︰The main clinical manifestations include dryness and lack of moisture in the eyes, sluggishness and discomfort, easy fatigue when viewing objects, complexion shallow yellow, pale nail color, insomnia dreamfulness, dizziness tinnitus, dry throat and tongue, or vexing heat in the chest, palms and soles, or sore waist and seminal emission. The tongue is pale or red, and the pulse is thin and rapid. The main disease causes are:
   1. excessive reading and eye use, prolonged viewing damages blood;
   2. excessive alcohol consumption and indulgence, leading to deficiency of yin essence;
   3. prolonged sorrow and crying, depleting body fluids over time;
   4. worry thought damaging the spleen, resulting in insufficient generation and transformation.
   The key diagnostic points are dryness and lack of moisture in the eyes, sluggishness and discomfort, and fatigue when viewing objects, accompanied by dry throat and tongue, insomnia dreamfulness, and a thin, rapid pulse. The treatment should focus on nourishing blood, promoting blood circulation, and nourishing water to moisten wood. The recommended prescription is Four Ingredients and Five Seeds Pill.
2. Dryness-heatdamage to Fluid︰The eyes are dry and itchy, with heat and astringency; dry cough with scanty sputum; dry mouth and nose; thirst with desire to drink; a red tongue with scant fluid; and a rapid pulse. This is mostly caused by exposure to dryness-heat pathogens. Dryness corresponds to the lung, which belongs to metal in the Five Phases. When metal is excessive, it overacts on wood. Since the eyes are the orifices of the liver, dryness pathogens easily take advantage. As stated in *The Guide to the Silver Sea: Dryness*: "The white of the eye belongs to the lung; when dryness is present, eye discharge becomes dry and itchy." Therefore, the key diagnostic points are dryness, heat, and itchiness in both eyes; dry mouth and nose; thirst with desire to drink; and dry cough with scanty sputum. Treatment should focus on clearing heat and moistening dryness, and the formula of choice is Dryness-Clearing Lung-Rescuing Decoction.

bubble_chart Documentation

1. Lingshu-Kouwen: "The eyes are the gathering place of the ancestral vessels and the pathway for the upper fluids... Therefore, when grief, sorrow, and worry stir the heart, the heart stirs and the five zang and six fu-organs all shake. When they shake, the ancestral vessels are affected, and when the ancestral vessels are affected, the fluid pathways open. When the fluid pathways open, tears and nasal discharge flow out. Fluids are what nourish the essence and moisten the orifices. Therefore, when the pathway for the upper fluids opens, tears flow. If the tears do not stop, the fluids are exhausted. When the fluids are exhausted, the essence is not nourished, and when the essence is not nourished, the eyes cannot see. Hence, it is called 'depletion of essence.'"
2. Shenshi Yaohan．Bai Tong: "White xerotic syndrome, without swelling or redness, without relief, with dryness, grittiness, and blurred vision, is called white dryness. The qi aspect is hidden, and there is dampness-heat in the spleen and lungs."

bubble_chart Differentiation

Although blurred vision and dry eyes often occur simultaneously, blurred vision is primarily characterized by unclear and dim vision, while dry eyes are mainly characterized by dryness, lack of moisture, and discomfort. There are still certain distinctions between the two conditions. Therefore, blurred vision is discussed in a separate section and is not within the scope of this article.