What are GP Contacts & How Do They Work?

Gas Permeable Contact Lenses

Posted Mar 6, 2018 | Tips, Tricks & Tech

Gas permeable contacts are made of a rigid silicone material that holds its shape and allows ample oxygen to reach the cornea. Also known as GPs or RGPs (rigid gas permeable), many people find that they provide excellent vision and value. They’re incredibly durable, with a single pair lasting up to two years. Gas permeable contacts are a better choice for people with certain eye conditions, such as keratoconus (a misshapen cornea). Interested in learning more about gas permeable contacts? Keep reading.

How Do Gas Permeable Contacts Work?

 Gas permeable lenses are different from soft contacts in two major ways:

  1. They maintain their shape in your eyes.
  2. Oxygen easily passes through the lens to the cornea.

What’s the secret to these unique characteristics? GP contacts are made of a rigid, water-permeable silicone. When it comes to correcting vision, they work the same as any other contact lens: refraction focuses light on the surface of the retina. However, their stiff structure keeps them from deforming and ensures sharp vision after every blink.

Pros & Cons of Gas Permeable Contacts

Gas permeable contacts have a lot of advantages over other designs, including:

  • Excellent quality of vision. The rigid lens provides consistently clear vision. Soft contacts may flex or contract, which can cause blurriness.
  • They’re built to last. Gas-permeable contact lenses can be worn for up to two years (with proper care).
  • Less prone to infection. A steady supply of oxygen to the surface of the eye slows the growth of bacteria.
  • Resistant to protein buildup. Substances have trouble sticking to gas permeable contacts, making for a clearer view.
  • More durable than soft contacts. It’s difficult to tear a gas permeable lens because of its rigid design.

Here are some common complaints about gas permeable contact lenses:

  • It takes time to adjust. GP lenses are smaller than soft contacts, so you can feel their edges when you blink. This can· be disconcerting at first, but most people get used to it and enjoy wearing GPs.
  • Debris can get underneath the lens. Since gas permeable contacts are small, they move around a bit. This creates opportunities for dust to get beneath the lens.

When Do Eye Doctors Prescribe Gas Permeable Contacts?

The rigid nature of gas permeable contacts makes them well-suited for multifocal and bifocal prescriptions. GPs are often the only choice when trying to correct blurry vision caused by keratoconus.

Where Can You Buy Gas Permeable Contacts?

Gas permeable contacts aren’t as easy to find as soft lenses, but your eye doctor can write a prescription and place an order. Has it been a while since your last eye exam? Eyeconic can help you find an optometrist or ophthalmologist nearby. 

Trying contacts for the first time? We created Contact Lenses 101 to answer all your questions about lens types, contact care, and more.