C.A.B.: a practical contact lens option?

The rigid contact lens continues to offer many prescription features which are difficult to match in the flexible lens realm, e.g.,: readily measured parameters, predictable optics, low production cost and minimum patient care requirements for reasonable hygienic safety. But poor tear pump efficiency remains a challenge in many conventional (i.e., PMMA) cases, even today. Oxygen permeable rigid materials represent the obvious solution to this problem, but how adequately do they perform? Two such materials are examined in this report in relation to the oxygen needs of the cornea.