Menicon Z is a hyper-oxygen permeable gas permeable (Dk 163) lens that offers comfort, wetability, long term eye health and clear crisp vision even if you have astigmatism. Menicon Z offers the highest level of oxygen permeability in a gas permeable lens material available today. Though it is most often worn on a Daily Wear (DW) basis, Menicon Z is approved for extended wear up to 7 days, and up to 30 days of continuous wear. Approved for ROSE K and CRT lenses.