Barrer


Barrer 

A unit of oxygen permeability of a contact lens material. Symbol: Dk. It is equal to the product of the diffusion coefficient D of oxygen through the material (i.e. the speed at which oxygen molecules pass through the material) and the solubility k of oxygen in the material (i.e. the number of oxygen molecules that can be absorbed in a given volume of material). See oxygen permeability; oxygen trans-missibility.