A pinguecula is often referred to as a fatty degeneration of the conjunctival tissue, but it may also reflect deposits of lipids from serous exudate. The fine, nearly transparent collagen fibers of the conjunctiva degenerate and are replaced by thicker, yellowish, more durable fibers and sometimes calcium crystals. This causes the elevated, yellow and sometimes whitish glistening area located near the cornea. There is no effect on vision by a pinguecula, which can appear after only a brief exposure to damaging irritation, such as excessive dryness or sun (ultraviolet radiation). The tissue damage increases with continued exposure.It might take only a day or two to notice a new pinguecula but weeks or months for it to resolve. Removing the source of irritation and providing artificial lubricating drops may shrink and eliminate pingueculae in their early stages; however, long-standing pingueculae do not respond well to treatment and may be permanent. Pinguculae may indicate vitamin A deficiency.