Chemical and viscometric studies were carried out on the vitreous bodies of 42 human post-mortem eyes. The age range in this series, which included normal and myopic eyes, was from newborn to 85 years old. In all cases, the vitreous body was divided into two portions, viz. cortical layer and central portion, for the various determinations. The findings of previous investigators that the concentrations of proteins and hyaluronic acid (calculated from the hexosamine content) are higher in the cortical layer than in the central region were confirmed. Very little collagen could be detected in the cortical layer, almost all of it being in the central portion. In confirmation of previous investigations, the viscosity numbers of the central region were found to be higher than those of the cortical layer in normal eyes. The concentrations of both collagen and hyaluronic acid were very low in the infant group (0–2 years old), but they appeared to reach adult levels by the age of 13. In contrast, the protein levels at birth were nearly equal to those of adults. Although the total amounts of protein, hyaluronic acid and collagen in the central portion were nearly the same in myopic and nonmyopic eyes, the concentrations of all three were considerably lower in the myopic group. In 5 of the 7 myopic eyes studied, the viscosity number of the cortical layer was higher than that of the central portion.