The medicinal part of cassia seed is its dried seed, mainly has the effect of clearing heat and brightening eyes (to get rid of the body’s heat evil, and promote the recovery of eyesight), laxative effect, mostly used for the red eyes and astringent pain, shyness and tearfulness (the eyes are afraid of the light, and often tears), headache and dizziness, dark eyes, and constipation. Cassia seed is the dried mature seeds of the legume Cassia obtusifolia or Cassia minor, which is sweet, bitter, salty, slightly cold in nature, and belongs to the liver and large intestine meridians, with the effect of clearing away heat and brightening the eyes, moistening the intestines and relaxing the bowels, and is often used for the treatment of red and astringent pain in the eyes, shyness and excessive tearing, headache and vertigo, darkness and uncertainty of the eyes, and constipation of the bowels. Spleen and stomach cold (spleen and stomach weak cold) and loose stools (feces thin not shaped) should not be served. Clinically, cassia seeds are often paired with chrysanthemum, flaxseed, Xia Gu Cao, stone cassia and other medicinal herbs, the specific use of the physician should also be under the guidance of the diagnosis, not blindly used on their own.