Lactate is the most abundant organic anion in the aqueous, and its concentration there is always higher than that in plasma. The high lactate level in aqueous is a result of glycolytic metabolism, upon which the avascular lens depends.
Ascorbate (vitamin C) levels in aqueous are much higher (some 10–50 times higher) than those in plasma. Ascorbate has antioxidant properties, and its high concentration in the aqueous protects intraocular structures by blocking UV light.
Excerpted from BCSC 2020-2021 series: Section 2 - Fundamentals and Principles of Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.