bubble_chart Concept

Fog moving before the eye (vitreous opacity) refers to a condition where the external appearance of the eye is normal, but the patient perceives a floating cloud-like or fly-wing-like shadow, or fluttering ribbons and rings in the air.

This symptom is referred to as "fly-wing like shadow (vitreous opacity)" in Yinhai Jingwei, and as "fog moving before the eye (vitreous opacity)" in Zhengzhi Zhunsheng, with detailed discussions. Later medical practitioners mostly followed these interpretations. Additionally, it is also called "black flowers before the eyes," "fly-wing like shadow (vitreous opacity) internal visual obstruction," "scattered flying flies," or mentioned under "visual hallucinations."

If severe fog moving before the eye (vitreous opacity) caused by bleeding leads to blindness, it falls under "sudden blindness." For more details, refer to that entry.

bubble_chart Pattern Analysis

1. Liver-kidney Depletion︰The eyes appear normal externally, but the patient subjectively perceives dark, mosquito- or fly-like shadows fluttering in front of them, which move upward when looking up and downward when looking down. Blurred vision is present, and prolonged use of the eyes leads to dryness, heaviness, and pain. Accompanying symptoms may include dizziness, tinnitus, weakness in the lower back and knees, nocturnal emission, a red tongue with scant coating, and a thin-weak or empty-large pulse. The treatment principle is to tonify the liver and kidneys. The recommended formula is Water-Supplementing and Spirit-Calming Decoction with the addition of mulberry fruit and black sesame, or alternatively, Eyesight-Improving Rehmannia Pill.
2. Deficiency of Both Qi and Blood︰The bilateral appearance is normal, but there are often dark shadows resembling flies, snakes, or silk threads lingering in the peripheral vision. The eyeball feels dull pain and dryness, extending to supraorbital ridge pain, which worsens with prolonged visual use. The complexion is dull, accompanied by shortness of breath, reluctance to speak, palpitation, insomnia, a pale tongue, and a soggy, thin pulse. The treatment should focus on tonifying qi and nourishing blood, using Ginseng Nutrient-Nourishing Decoction or formulas that tonify and replenish qi and blood.
3. Damp Phlegm︰There is a fluttering sensation in front of the eyes resembling flags, butterflies, or mosquito wings, with a slightly yellowish hue, while the appearance of both eyes remains normal. Accompanied by a heavy and uncomfortable sensation in the head, reluctance to open the eyes, excessive phlegm, chest tightness, mental fatigue, anorexia, loose stool, a greasy or white-slippery tongue coating, and a slippery pulse. The treatment should focus on eliminating dampness and transforming phlegm. The recommended formula is Gallbladder-Warming Decoction plus White Atractylodes Rhizome, Bile Arisaema, and sea pumice.
4. Dampness-heat︰Frequently, there are spider silk-like floaters drifting and mosquitoes or flies fluttering before the eyes, moving or stopping with the movement of the eyeballs, blurred vision as if looking through a thin veil or mist. Common symptoms include hyperemia of ocular conjunctiva, or ciliary hyperemia, headache, eye pain, photophobia, and contracted pupil (iridocyclitis). Accompanied by bitter taste in mouth, irritability, dark urine, white and greasy tongue coating, and a soggy, slippery, rapid pulse. Treatment should focus on clearing heat and draining dampness. The prescription can be the secret formula Polyporus Decoction with the addition of Sophora and Talc powder, or Gentian Liver-Draining Decoction with modifications.

In the condition of fog moving before the eye (vitreous opacity), the first clinical step is to differentiate between deficiency and excess. Deficiency is generally caused by liver-kidney depletion and dual deficiency of qi and blood. Excess is often attributed to internal phlegm-dampness, which may manifest as turbid phlegm or dampness-heat. Grasping these key points makes differentiation straightforward.

bubble_chart Documentation

1. Zhengzhi Zhunsheng-Floating Clouds and Shifting Fog: "…It is due to injury in the Xuan Fu (mysterious mansion), where the essence-fluid between the collaterals is depleted and stagnant, impairing the clear and pure qi, thus leading to internal obstruction. Its origin lies in the gallbladder and kidney. Black [manifestations] indicate disorders of the gallbladder and kidney themselves; white [manifestations] arise from phlegm-fire damaging the lung-metal’s insufficient clarity and purity; yellow [manifestations] result from injury to the clear and pure qi of the spleen and stomach affecting their collaterals."