GAS PERMEABLE
CONTACT LENSES
WHAT ARE RIGID GAS PERMEABLE (RGP) LENSES ?
Rigid gas permeable contact lenses (RGP) are made of a durable rigid, oxygen permeable plastic. They can come in many sizes but all are smaller than the iris (the colored portion of your eye), and they sit gently on a layer of tears that is in front of the cornea (the clear anterior surface of the eye).
RGP lenses have the unique ability to mask a multitude of visual irregularities due to corneal astigmatism, corneal scarring, conditions of the cornea including keratoconus, post-surgical abnormalities, and many more.
The tear film is what makes the vision so clear when wearing RGP lenses. Below the RGP lens, tears fill in anterior surface irregularities and create essentially a "new"corneal surface that is smooth and allows light rays to hit the retina in a straight line. Even people with no corneal issues can benefit from the intense clarity of these lenses.
HOW LONG DO RGP LENSES LAST?
Rigid gas permeable contact lenses can last for as long as: your corneal shape doesn't change, your prescription doesn't change, and the material remains unscratched. These lenses are very high quality and an excellent investment in clear, comfortable vision.
Unless there are change, we usually recommend getting a new pair every two years as well as having backup pair, especially if you have an ocular condition and rely on these lenses to see.
WHO CAN BENEFIT FROM RGP LENSES?
1.) Anyone who feels they cannot see clearly with conventional soft lenses.
RGP lenses has the unique ability to minimize any imperfections on the front surface of the eye, including astigmatism or very mild corneal dystrophies.
For some people, soft contact lenses just do not provide the clarity they are hopeful for, especially when fit with a multifocal lens (lenses for distance and near). These lenses offer superior optics.
2.) Ocular conditions with irregular corneas such as: keratoconus, corneal transplants, radial keratotomy, corneal scarring, etc.
Irregular corneas bend light rays so they are unable to reach the retina in a straight line, making images distorted and blurry. For this reason, glasses are ineffective because once the light rays go through the glasses, they still are obscured by the cornea.
RGP lenses are a great option to restore vision to people with irregular corneas. Between the keratoconic cornea and the lens, the liquid "fills in" the irregular surface to create a "new" corneal surface, where light can pass through clearly to the retina.
3.) High Prescriptions: High Myopia (Nearsightedness), High Hyperopia (Farsightedness), or High Astigmatism
Those with very high prescriptions are sometimes unable to be fit with conventional soft contact lenses. RGP lenses can be designed with extremely high prescriptions, providing a correction that would be superior to glasses and soft contact lenses for these patients.
Q: WHAT IS THE FITTING PROCESS LIKE?
A: The fitting process starts with a Specialty Contact Lens Consultation. This consultation covers all testing necessary to determine the best option to perfect your vision. You may try on different types of lenses at this examination as well to assess your visual potential.
If you decide to proceed with contact lenses, the lenses are ordered for you and you will return in about 1-3 weeks to try on the initial lens. This initial lens is our first chance to see how things look. If the lenses looks good you will leave with the lenses and return for a follow up visit to give us feedback on comfort and vision. We may need to alter the lens at this visit and will order lenses with different parameters.
For specialty contact lenses, once we start the fitting process you are able to return for unlimited follow ups and lens changes for three months until we have a final product.
Our Patient Success Stories with RGP lenses:
This was a young 39 year old patient who came to us wearing the lens entitled "spherical back". This means that although they had a lot of astigmatism, the back surface of their RGP lens had only one size. This resulted in a poor fit and the patient having to wear reading glasses because of an incorrect prescription.
We fit this patient in an RGP lens with a back surface that has two different shapes to match their astigmatism (toric back picture). See how much better this lens fits and how even the green tear film is underneath? This patient was able to achieve better vision, more comfort, and not need reading glasses anymore.