Definition of gas-permeable in US English:
 gas-permeable
adjectiveˈˌɡas ˈpərmēəbəlˈˌɡæs ˈpərmiəbəl
(of a contact lens) allowing the diffusion of gases into and out of the cornea.
 Example sentencesExamples
-  The lids and/or bottom surfaces contain steam- or gas-permeable, high-efficiency microbial filters.
 -  Daily-wear soft lenses aren't as durable as gas-permeable lenses, but are more durable than disposable soft lenses.
 -  I wore hard, then gas-permeable, lenses for years, and never had a problem with them until the last year or so.
 -  All soft lenses are gas-permeable to a certain degree, and can be categorized further by the amount of water in the material.
 -  Rigid or gas-permeable contact lenses appear to slow the development of axial myopia to a greater extent than bifocals, but the reason is unknown.