Hard Contact Lens

1. Rigid Gas Permeable (GP) or Oxygen Permeable Contact Lenses
Hard contact lenses were made of a material known as PMMA. Before 1971, when soft contact lenses were introduced, just about all contact lenses were made

2. Contact Lenses for the Hard-to-Fit Patient - AllAboutVision.com
Contact lenses for people with astigmatism, presbyopia, giant papillary conjunctivitis (GPC), keratoconus or post-surgery problems.