Glossary

翳, Yi means a screen, cover or barrier while 目, Mu relates to vision. In medicine it refers to any disorder where vision is impeded by a thin membranous growth, generally translated as a Nebula, Shade or Eye Screen. They can be divided into several subtypes including:

• 凝脂翳 Ning Zhi Yi: Congealed Fat Screen
• 氣翳 Qi Yi: Qi Screen The Mou Jing Da Cheng by Huang Tingjing (1741) describes this as red eyes, with pain, and tears, a turbid smokey death-like colour and faint pupil but with no physical obstacle to remove surgically. It is caused by Wind-Heat or Damp-Heat in the Liver, or long-term stagnation that damages Yin, and blood stasis. For Wind-Heat in the Liver it is treated with Sheng Di Huang powder, for severe Heat and Blood Stasis it is treated with Long Dan Xie Gan Tang, for Yin deficiency it is treated with honeydew drinks and Tu Fu Ling.
• 宿翳 Su Yi: Old Screen
• 新翳 Xin Yi: Fresh Screen
• 圓翳 Yuan Yi: Round Screen
• 天行赤眼暴翳 Tian Xing Chi Yan Bao Yi: Epidemic Fulminant Red Eye Screen
• 圓翳內障 Yuan Yi Nei Zhang: Round Screen with Inner Barrier Refers to a hard physical obstruction, generally understood to be cataracts. The Wai Tai Bi Yao by Wang Tao in the Tang Dynasty cites a Daoist named Xie who said the main treatment for cataracts once they had developed was surgery, using a "sickle method" to remove them. However, it was rarely performed and the preferred approach was to treat the internal causes early before reaching the stage where they become difficult. For cataracts specifically it recommends:

  "take 'Pills with Da Huang.' It is not advisable to induce a severe drainage. This illness is always the result of a depletion heat coupled with wind" (Kovacs & Unschuld, 1998, Essential Subtleties of the Silver Sea).

  particularly of the Liver which opens into the eye. Several modern TCM formulas are used to prevent and aid recovery from cataracts (Liu, Shi & Li, 2024)