Gas Permeable (GP) or Rigid Gas Permeable (RGP) contact lenses are an alternative to soft contact lenses that are made from a hard, oxygen permeable material. GP lenses are less common than soft lenses but offer a number of advantages and are continuing to improve as research and technology advance. Many people grew up wearing these lenses as children, but as the technology for soft lenses improved, they switched and left hard lenses behind. Hard contacts aren’t for everyone, but they meet a significant number of needs for patients who might otherwise have their vision needs unmet with conventional soft lenses. In some cases, hard lenses provide superior vision even to glasses!
The combination of total customization, and strong materials means that hard lenses offer a number of advantages over soft contact lenses.
Why your doctor or fitter might choose an RGP for you
Health and Hygiene
Unlike soft lenses, GPs don’t contain water which makes them less likely to attract and breed bacteria that can cause eye infections.
Due to the rigid material, GPs have a smooth surface and maintain their shape, providing sharp and stable vision. Because soft lenses have a significant water content, the quality of vision decreases the stronger a prescription is. Patients with moderate to severe prescriptions often find that they prefer the quality of their vision in a hard lens rather than a soft. In addition they do not dehydrate, which is often a cause for reduced vision with other lenses.
Because they last so long, hard lenses are much more cost effective than soft lenses, especially disposable lenses that require a constant supply. If they are maintained properly, and well cared for, they can last 2-3 years before needing a replacement. Even if you feel that “nothing has changed” our office recommends a reevaluation and replacement pair because these lenses can become warped after 3 years. Because they are made to order, there is an initial cost investment and they will take up to a week to manufacture if you do need a replacement pair. If you are heavily dependent on your lenses, please take the time to seriously consider a 2nd, back up pair. Life happens. Be prepared.
GPs for Astigmatism
Conventional soft lenses can be thought of as “one size fits most.” Often, patients who are not in the “most” category are told that they can’t have contacts which we think is an absolute shame! Hard contacts lenses are ideal for individuals with high prescriptions and excessive astigmatism who may have been told that they cannot wear soft contacts. Because of the rigid nature of the lens, they hold their shape on the eye allowing for more clear and stable vision correction.
Adapting to GP lenses
One of the downsides of GP contact lenses is that they require an adaptation period, particularly if you are used to soft lenses with a larger diameter. One of the major differences is an experience of “lens awareness” in which you feel the edge of the lens when you blink. It could take up to a few weeks to get used to the lenses but many people report that after this initial period they find that GP lenses are just as if not more comfortable than soft lens varieties.
If your first set of hard lenses are not comfortable, please do not give up on them! This adaptation takes time. If you stick it out and commit yourself, your doctor or fitter can and will, make adjustments to the shape, size, thickness, and material of the lens to maximize your comfort. There is a major difference between “lens awareness” and actual pain and discomfort. When a hard lens has been PROPERLY fit, it should not hurt you even if you can still feel it.
GP contact lenses are custom made for each patient based on the eye’s individual curvature, size, and corneal shape.
GP lenses have a smaller diameter than soft contacts, meaning that they cover less of the surface of your eye. While this may take some time getting used to initially, ultimately many find that they are just as if not more comfortable than soft contacts.