FROM previous investigations1 it is known that corneal transparency is due largely to a certain physicochemical condition of the connective tissue of the cornea. The water content of the corneal connective tissue is regulated by the adjacent living tissues (epithelium and endothelium) which Cogan and Kinsey1e showed to be impermeable to chloride and permeable only to water.
Ophthalmologists often observe the great power of the connective tissue of the cornea to absorb water. This power must be ascribed to the absorbing properties of the intermediate substance, which consists chiefly of two components, the collagen and the mucoid. The collagen, split up into loose bundles of fine fibers, lies enmeshed in the mucoid. The mucoid not only fills, as a gel, all spaces between the fiber bundles but also penetrates the bundles and takes part perhaps in the formation of the micelles of the intermediate substance itself. According to
VAN WALBEEK K, NEUMANN H. STUDIES OF CORNEAL TRANSPARENCY UNDER VARIOUS EXPERIMENTAL CONDITIONS. AMA Arch Ophthalmol. 1951;46(5):482-487. doi:10.1001/archopht.1951.01700020495002