Initially, contact lenses were made from hard or rigid plastic materials. In the beginning all hard contact lenses were made of polymethylmethacrylate(PMMA). Although this material was very durable, it did not allow oxygen to pass through the lens to your eye. As a result many complications occurred and often these lenses were very uncomfortable to wear. We no longer fit PMMA (hard) lenses but we do fit oxygen permeable rigid lenses. These lenses do allow your eye to breathe, are very healthy for your eyes and vision is typically crystal clear. New advancements in design and manufacturing have made rigid gas permeable(RGP) contact lenses more comfortable. These lenses provide excellent options for people with astigmatism and bifocals in their prescription. In addition, RGP lenses can be worn for extended periods of time and even for overnight wear. They also are very useful in correcting problems due to refractive surgery.