Hard contact lenses that are made of silicone-containing compounds which allow oxygen to pass through the lens material to the eye are Gas permeable (GP) contact lenses, or rigid gas permeable (RGP) lenses. GP lenses offer a number of advantages over soft lenses although many people in Northern Colorado do not prefer them over soft contact lenses.
Advantages of gas permeable lenses
- GP lenses allow your eyes to “breathe” better. Take a moment and consider how important breath is to the human body. Our eyes need oxygen as well. A lack of oxygen to the eye can cause eye problems due to hypoxia (reduced oxygen supply). Most soft lenses supply less oxygen to the eye. Gas permeable lenses provide a better oxygen supply than most soft contact lenses because of the following:
- The use of silicone in the lens materials of GP lenses allows GP lenses to give your eyes greater access to oxygen compared to many soft lenses available, (though new “silicone hydro-gel” soft lenses are comparable to GPs in oxygen transmission).
- GP lenses cover less of the front surface of the eye (the cornea) because their diameter measures smaller exposing more of the naturally to oxygen.
- Tears, containing oxygen are allowed to move under GP lenses with each and every blink. Soft lenses in comparison allow very little to no tears under the lens giving the eye less access to oxygen when you blink.
- GP lenses provide sharper vision. When GP lenses are made they use a custom-machining technique to create a smooth surface so that the lenses maintain their shape on the eye. Because of the custom machining GP lenses are able to provide sharper vision than soft lenses, which have the ability to change shape and clarity of vision when they get too dry. Astigmatisms are better treated by GP lenses as they give a longer lasting and accurate correction of vision.
- GP lenses last longer. The rigidity and ease of cleaning make GP lenses a great choice for long term use. One pair of GP lenses can easily last a year or more. Because GP lenses are long lasting they can be a less expensive option long term.
- GP lenses may slow the progression of nearsightedness. Some research has found that in some cases involving children, wearing GP lenses can actually slow the progression of myopia (nearsightedness). In orthokeratology GP lenses are used. They are specially designed contacts that are worn while you sleep to gently reshape the cornea and over time improve vision.
The downside of GP contact lenses
Why do some people in Fort Collins, Loveland and Greeley choose soft lenses? Let’s take a look at the reasons why you may choose soft lenses over GP lenses:
- Need for adaptation. When wearing soft lenses you would find that they are comfortable from the first time you wear them. GP lenses, on the other hand can take weeks to achieve that same level of comfort. However, most people say that their vision is clearer and that the GP lenses are actually MORE comfortable that the soft lenses after a few weeks of wear (while their eyes adjust). You may find that when you start wearing GP lenses you can only wear them for a couple of hours a day and each day the time span of wearing increases with comfort until you are able to wear them all ay with no problem and in complete comfort.
- Inability to wear part-time. In order for your eyes to adjust fully to GP lenses and to experience a high level of comfort while wearing them you will need to wear them every day. If you decide to stop or pause use for a few day and then start up wearing them again, you will have to go through some readjustment of your eyes to the lenses again.
- Increased possibility of dislodging. GP lenses are smaller in diameter that soft lenses and so they have a higher probability of dislodging if you rub your eyes vigorously or play an aggressive sport.
- Vulnerability to sand and dust. Because GP lenses are rigid they don’t take on the total shape of your eye like soft lenses. This can allow sand or dust to get under your contact lens on a very windy day or when you are on vacation at the beach. (this can be minimized by simply wearing wrap-style sunglasses when outdoors.)
- Higher lens replacement costs. GP lenses are custom made to the measurements of your specific eyes. Soft lenses are made uniformly in batches and so they are significantly less expensive. Because of the customization of the lens GPs are more expensive to replace if they are lost or damaged. It can also take about a week to replace GPs. It is always good to be prepared and purchase a spare pair so that you don’t have to wait and be without contacts until your order can be filled.
Best of both worlds?
Here in Fort Collins, Loveland and Greeley hybrid lenses are also available. They have a GP center and so they offer the customization, clarity and long term comfort of GP lenses, coupled with a soft outer “skirt” which gives the Hybrid an increase in immediate comfort and wear ability.
Call for more information and a trial fitting
To see if gas permeable lenses are right for you, call our office at 970-204-4020 for more information and to schedule a trial fitting.Or click on the link on the side of this page.