Human cornea: individual responses to hypoxic environments.

Using a micropolarographic system, the responses of seven human corneas to oxygen atmospheres ranging from 20.9% to 0% were measured. Under normal atmospheric conditions, ratios of oxygen demand were observed between corneas as great as 1.23:1. Following 0% oxygen conditions, however, these ratios rose to a maximum of 1.93:1, i.e., representing demand differences between particular corneas of nearly 2:1. Such differences may prove increasingly important in the gauging of patient suitability and safety in relation to hypoxic stress, e.g., the extended wear of contact lenses.