POSSIBLE CAUSATIVE FACTORS
Little is known about what causes the changes in the vitreous with age, and what can speed up or slow down the process. It is relatively easy to speculate on some potential causes. It is known that excessive exposure to sunlight can cause damage to the eyes and skin, and is a contributor to cataract formation and drying, wrinkling skin. There is no reason to think that these types of effects could not occur in the vitreous to some extent, perhaps contributing to the clumping of the collagen fibers and the drying of the fluid. Hence, a rational protective effort would be to utilize good quality sunglasses and, in cases where there is considerable exposure to sun, to utilize shading (such as a visor or hat). Similarly, one should be careful about exposure to bright lights from copy machines, lasers, and other indoor sources. The drying of fluid within the eyes may be accelerated by poor circulation in the retina (capillary bed circulation) and by general lack of hydration. Blood circulation can be worsened by high blood sugar, high blood fat, and high oxidative levels in the blood, while it can be improved by maintaining healthy blood conditions and having a diet rich in flavonoids and antioxidants; hydration is improved by drinking plenty of water, juice, tea, or other healthy beverages. Thus, protecting the eyes and maintaining good circulation and hydration are potential preventive measures for floaters, retinal tearing, and retinal detachment.

CHINESE MEDICAL VIEWS
In the Yinhai Jingwei (Essential Subtleties on the Silver Sea), a text on ophthalmology from the time of the Ming Dynasty (1), there is a discussion of floaters, described as "black blurred specks in the eyes resembling fly wings." The pathology is said to be related to the "water of the kidney" refers to the kidney yin, as distinguished from the "fire of the kidney," which corresponds to the kidney yang or mingmen fire:

[Floaters] are a sign of weakness of the water of the kidney. The kidney is the mother of the liver. If the water of the kidney can not nourish the wood of the liver, the liver will display deficiency heat. The gallbladder lies beside the liver. If the wood of the liver is withered and parched, the qi of the gallbladder will be insufficient. As a result, whenever one starts or halts a movement of the head, black specks resembling fly wings float in the spirit water of the eyes. To regulate this condition, one must first employ Zhuling San (Polyporus Powder) to return the evil fire in one's liver and in the kidney to normalcy. Next, one employs Heishen Tang (Scrophularia Decoction) to cool the liver. Then the conduit of the gallbladder will no longer be invaded by evil heat. Afterward, one employs Bushen Wan (Supplement the Kidney Pills). Then the black specks will disappear by themselves.

The formulas mentioned for this condition are as follows:

Zhuling San (Polyporus Powder) Polyporus 30 g Akebia 30 g Rhubarb g Gardenia 30 g Cibotium 30 g Talc 30 g Polygonum 30 g Plantago seed 15 g Red atractylodes 15 g	Instructions: grind the ingredients to powder; one dose is 9 grams, to be consumed with salty water. Actions: This formula clears damp-heat of the liver/gallbladder and the kidney/bladder; it is comprised mainly of bitter herbs of cold nature. Most of the herbs are classified as diuretic in modern terms; rhubarb and gardenia purge the gallbladder.
Heishen Tang (Scrophularia Decoction) Scrophularia Scute Raw rehmannia Chrysanthemum Red peony Celosia Tribulus	Instructions: to grind the ingredients in equal parts to powder. Each dose is 12 grams, with the powder boiled in water for a brief time and the resulting decoction consumed. Actions: These herbs clear heat from the blood and dispel wind-heat from the eyes.
Bushen Wan (Supplement Kidney Pills) Ginseng Acorus Hoelen Lycium Peony Cuscuta Alisma Cistanche	Instructions: grind equal amounts of these herbs to powder, mix with honey to form pills. The quantity of the herbs to be used for each dose is unclear. Actions: This formula nourishes the kidney and moistens the essence.