Meaning of gas-permeable lens

gas'-per•me•a•ble lens'

Pronunciation: (gas'pûr"mē-u-bul), [key]
  1. a semisoft contact lens, usually removed each day, that allows air to pass through to the eye and affords a wider range of vision corrections than a soft contact lens.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.