About This Formula
Traditional Chinese Medicine background and properties
Formula Description
A classical formula used to improve night vision and nourish the eyes. It combines herbs that replenish Yin fluids, warm Kidney Yang, and dry Dampness to treat poor night vision (night blindness) caused by a combination of Yin deficiency and Dampness obstructing the eyes.
Formula Category
Main Actions
- Nourishes Yin and brightens the eyes
- Supplements the Kidneys and strengthens Yang
- Dries Dampness and strengthens the Spleen
- Benefits Essence to improve vision
TCM Patterns
In TCM, symptoms don't appear randomly — they cluster into recognizable patterns of disharmony that reveal what's out of balance in the body. Shi Hu San is traditionally associated with these specific patterns.
The following describes this formula's classification within Traditional Chinese Medicine theory and is provided for educational purposes only.
Why Shi Hu San addresses this pattern
Night blindness (雀目) in TCM is closely linked to Liver and Kidney Yin deficiency. The Liver opens to the eyes, and the Kidneys store the essence that nourishes them. When Kidney Yin is depleted, insufficient essence reaches the Liver and eyes, leading to dimness of vision, especially in low light. Shi Hu San addresses this by using Shi Hu to directly nourish Kidney and Stomach Yin, generating the fluids and essence needed to nourish the eyes. Xian Ling Pi supports Kidney Yang to ensure that essence is actively transported upward. Cang Zhu clears any turbid Dampness and supports the Spleen's role in nourishing the eyes with clear Qi.
A practitioner would look for one or more of these signs
Clear vision during the day but progressive dimness at dusk and inability to see at night
Gradual decline in visual clarity, especially in dim light
Dryness and discomfort of the eyes due to insufficient Yin fluids
Mild dizziness or lightheadedness from deficient Kidney essence
Ringing in the ears, a common accompaniment of Kidney Yin deficiency
Weak lower back and knees indicating Kidney deficiency
Why Shi Hu San addresses this pattern
When both Kidney Yin and Kidney Yang are insufficient, the eyes lose their source of nourishment and warming Qi. The result is poor adaptation to darkness, as the Kidneys can neither generate the essence to nourish the eyes nor provide the Yang Qi to carry it upward. Shi Hu San uniquely addresses both aspects: Shi Hu replenishes Kidney Yin while Xian Ling Pi warms Kidney Yang. This dual approach makes the formula particularly well suited for patients who show signs of both Yin and Yang deficiency, such as feeling both cold and dry, or having weak night vision alongside cold extremities and a sore lower back.
A practitioner would look for one or more of these signs
Inability to see clearly at night
Lower back weakness from dual Kidney deficiency
Slightly cold hands and feet indicating Yang deficiency component
General tiredness from depleted Kidney Qi
How It Addresses the Root Cause
Night blindness (雀目, que mu, literally "sparrow eyes," because sparrows cannot see at night) was understood in TCM as a condition where the eyes function well in daylight but lose their ability to see in dim light. The underlying disease logic involves deficiency affecting the Liver and Kidneys, the two organ systems most closely tied to eye health in Chinese medicine.
The Liver "opens to the eyes" and stores Blood, which nourishes the visual faculty. The Kidneys store Essence (Jing), which is the deep constitutional resource that supports Liver Blood and generates the marrow that nourishes the brain and eyes. When Kidney Yang is insufficient, it fails to warm and activate the Liver's Blood-nourishing function, and the eyes lose their capacity to adapt in low light. At the same time, if the Spleen is weakened by Dampness, it cannot efficiently transform food into the Blood and Qi needed to sustain the Liver and eyes. The condition thus involves a triple deficiency: Kidney Yang failing to support the Liver, Liver Blood or Essence failing to reach the eyes, and Spleen Dampness obstructing the production of nourishing substances.
Shi Hu San addresses this by combining Yin-nourishing, Yang-warming, and Dampness-drying strategies in a single compact formula, restoring the flow of nourishment from the Kidneys and Spleen upward to the Liver and eyes.
Formula Properties
Slightly Warm
Predominantly sweet and pungent with mild bitterness — sweet to nourish Yin and generate fluids, pungent to warm Kidney Yang and dispel Dampness, bitter to dry Dampness and strengthen the Spleen.
Formula Origin
This is just partial information on the formula's TCM properties. More detailed information is available on the formula's dedicated page
