You’ve heard the term “gas permeable” thrown around a lot, and it sounds like it might indicate something important. Your optometrist talks about these lenses, and a few of your friends and neighbors swear by them. So you wonder-will these special contact lenses finally give you the comfortable fit you’ve always wanted?
Before you order these lenses from your optometrist, have a look at the information below. In many cases these lenses will help you have a better vision experience, but in others, you may do just as well with your current lenses.
Typical Contact Lens Problems
Most people switch to gas permeable lenses because they often or always experience the following eye problems.
Look in the mirror and examine your eyes. As you look at your pupil and iris (the colored part of your eye), you’ll notice that they have a clear covering, called the cornea. The cornea acts as a transparent lens that refracts light into your eye’s receptor cells, which interpret the light signals and send them to your brain as images. Without the cornea, you wouldn’t see very well.
The cornea stays transparent because it doesn’t have blood vessels running through it. However, it consists of living cells that still need oxygen-so how do those cells get the air they breathe?
The receptor cells absorb oxygen directly from the air outside your eye. They also exhale their carbon dioxide the same way. So if you cover your cornea with a contact lens, these cells can’t inhale or exhale properly. The process will slow or even stop, leading to damage.
You’ll know this has happened to your cornea if you notice the following:
- Changes in the cornea’s shape, including scarring
- Less transparency in the cornea
- Decreased ability to sense eye pain
- Blood vessels growing from the sclera (the white part of your eye) into your cornea
Gas permeable lenses let more air flow into and out of your eye, which puts you at a lower risk for developing these problems.
Your eyes regularly produce tears to clean away dust, bacteria, and other debris. However, when you wear contacts, the lenses block tears from cleaning the covered part of your eye, which can dry out. Contacts also pull moisture from your eyes to maintain their shape. And as moisture evaporates from your contact lenses, your eyes can dry out further. You may also notice the following symptoms:
- A burning, stinging, or scratching sensation in your eyes
- A sensation of having something in your eyes
- Redness and inflammation in the sclera
- Increased sensitivity to light, contacts, and other stimuli
- Excessive tearing
Sufferers often experience blurred vision as well. See your optometrist immediately if your vision starts to blur.
Gas Permeable Lenses to the Rescue
Contact lens manufacturers have developed many options that reduce your risk for developing the conditions listed above. However, gas permeable lenses allow more oxygen into your eye than most other options. However, because you probably use soft lenses like most contact wearers, you may find transitioning to these lenses difficult. Gas permeable lenses are rigid, not soft.
However, gas permeable lenses do have a number of advantages:
- They allow for up to 200 units of oxygen permeability, whereas soft lenses only allow up to 35.
- They don’t contain water because they don’t restrict your eyes’ ability to make their own-this quality makes them less likely to develop deposits and attract bacteria.
- They come with a customized shape and size. Your optometrist will measure them to the exact size, curvature, and corrective power that your eyes require.
- They last longer. They won’t tear or rip, and a single pair can last up to a year with proper care.
- Their rigid shape gives them crisper vision than soft lenses. This crisper vision also comes from the lenses’ exact match to your eyes’ curvature.
In some cases, gas permeable lenses can even slow nearsightedness’s development. But even though these lenses come with a myriad of benefits, they also have their disadvantages:
- They take longer to get used to because they’ll feel more obvious in your eye.
- They require daily wear, or your eyes won’t feel used to them anymore, leading to more discomfort.
- They feel worse than soft contact lenses when debris gets underneath them.
- They can fall out of your eyes more easily because of their smaller size.
- They often cost more than a typical soft lens, and they take longer to replace.
Once you get used to your lenses, they’ll feel just as comfortable as soft contact lenses. But if you don’t think you can manage these disadvantages, consider other options, like hybrid lenses or soft lenses with increased air flow, like Air Optix or Acuvue Oasys. You can also switch to eyeglasses to give your eyes complete freedom from any air or moisture restrictions.
To find out which option works best for you, contact your optometrist.