Library

1. The eyes gather the essence and qi of the five zang organs and six fu organs: the white part (sclera) is governed by the essence of the Lung, the black part (cornea and iris) by the essence of the Liver, and the pupil by the essence of the Kidney; blood collaterals converge at the inner and outer canthi (corners of the eyes), and the restraining function of the eyelids is governed by the essence of the Spleen. These essences connect via meridians to ascend to the brain and emerge from the nape. If there is heat in the meridians, the cou li (skin texture and pores) open, allowing wind pathogen to enter. It combines with internal heat and attacks upward to the eyes, causing redness, swelling, and pain. Mild cases manifest as external obstructions (wai zhang), generating cloud-like opacities (yun yi); severe cases result in sudden injury to the eye due to excessive accumulated heat.

[Note] The *Neijing* states: "The essence and qi of the five zang organs and six fu organs all ascend to the eyes to form vision." The eye structure is like a nest, wherein: the essence of Qi manifests as the white eye (bai yan/sclera), the essence of Sinew manifests as the black eye (hei yan/cornea and iris), the essence of Bone manifests as the pupil (tong zi), the essence of Blood manifests as the collaterals and canthi, and the essence of Flesh manifests as the restraint (yue shu/eyelids). These essences of sinew, bone, blood, and qi connect with the vessels, ascend to the brain, and exit from the nape. Because meridian heat steams and opens the cou li, wind pathogen is able to invade. Wind-heat pathogens combine and attack upward to the eyes, causing redness, swelling, and pain. Mild cases become external obstructions, or suddenly generate cloud-like opacities; severe cases involve very serious accumulated heat, suddenly injuring the eye painfully.

2. Huo Yan (Fire Eye) presents with redness, swelling, tearing, and astringent pain. Swelling that is hard indicates excess Heat, while swelling that is soft indicates excess Wind. Eyelids may initially show millet-like granules, or the margins may ulcerate, or there may be growths resembling chicken combs or clam meat, or pterygium (nu rou) grows with red vessels penetrating the pupil. Blood may flood the pupil, the eyeball may protrude high, or it may rise like a spiral shell tip, or the pupil may bulge like a crab's eye causing pain. Eyelashes may curl inward (quan mao), tears flow upon exposure to wind, itching caused by wind is unbearable, red membranes may droop downward, and yellow membranes may rush upward.

[Note] When Wind-Heat attacks upward, causing redness, swelling, pain, tearing, and difficulty opening the eyes due to astringency, this is Huo Yan (Fire Eye). Swelling that is hard belongs to Excess Heat and should first be treated with purgation. Swelling that is soft belongs to Excess Wind and should first be treated with dispersion. Initially, millet-like bumps appear on the upper and lower eyelids, gradually enlarging to rice-grain size, either red or white, with mild pain; this is called Jian Sheng Feng Su (Wind Millet on Eyelids). The two eyelids adhere to the eyeball, becoming red, ulcerated, itchy, and painful, persisting for years without healing; this is called Lan Xian Feng (Rotting Margin Wind), also known as Chi Xia. Inside the eyelids, tissue resembling a chicken comb or clam meat protrudes, obstructing vision and causing pain and photophobia; this is called Ji Guan Xian Rou (Chicken Comb and Clam Meat). All these are diseases caused by Wind-Heat in the Spleen Meridian. Fascia in the two canthi protrudes, called Nu Rou Pan Jing (Pterygium Climbing the Eye). Red vessels in the two canthi gradually invade the cornea, called Chi Mai Guan Jing (Red Vessels Penetrating the Eye). Both eyes are mixed red like cinnabar, with pain like needle pricking, called Xue Guan Tong Ren (Blood Flooding the Pupil). Both eyes itch and hurt, suddenly protruding high, called Tu Qi Jing Gao (Sudden Protrusion of the Eye High). Severe pain in the eye, suddenly generating an opacity shaped like a spiral shell, called Xuan Luo Jian Qi (Spiral Shell Tip Rising). Severe pain in the eye, suddenly the pupil bulges like a crab's eye, called Xie Jing Teng Tong (Crab Eye Pain), also known as Sun Yi (Damaged Opacity). All these are due to accumulated Heat in the Liver and Heart meridians. Dryness and tightness of the two eyelids, with eyelashes turning inward to prick the eyeball, called Dao Jie Quan Mao (Inverted Lashes and Curled Hairs). Exposure to wind causes tears to flow continuously, especially in winter, called Ying Feng Liu Lei (Tearing Upon Facing Wind). Extreme itching in both eyes and canthi without pain, called Feng Yang Nan Ren (Wind Itching Unbearable). A yellow membrane suddenly appears from below in the eye, invading the cornea and causing pain, called Huang Mo Shang Chong (Yellow Membrane Rushing Upward). A red membrane suddenly appears from above in the eye, drooping down to cover the cornea, called Chi Mo Xia Chui (Red Membrane Dropping Downward); also known as Chui Lian Yi (Drooping Curtain Opacity). All these are diseases caused by Wind-Heat in the Heart, Liver, and Spleen meridians.