Effect of blinking on the level of oxygen beneath hard and soft gas-permeable contact lenses.

The oxygen tension, which can also be stated as the equivalent oxygen percentage (EOP), was measured beneath a variety of hard and soft gas-permeable contact lenses following static and dynamic wearing conditions. The significant increases in EOP beneath rigid lenses upon blinking were to be expected in view of the tear pumping mechanisms known to exist with such lenses. However, blinking was found to have a minimal effect on the EOP beneath hydrogen lenses, confirming earlier predictions.