Rigid Gas Permeable (RGP) are often the first choice of custom lenses by your doctor or fitter for a variety of reasons.
The advantages of RGP lenses:
They are made to order. All of the curves are fabricated to fit your exact needs. Nearly every parameter can be changed by your doctor to maximize your experience with your lenses including prescription, materials, and coatings.
They are generally less expensive than the alternative options for custom lenses such as hybrids or scleral lenses. They are also more durable than traditional soft lenses and if well cared for, can last up to two years. We generally don’t encourage anything longer than that because the lens can start to warp imperceptibly and start to have a negative impact on the cornea.
Because soft lenses have such a high water content, they are often a poor optical medium for very high prescriptions. Your doctor or fitter might choose an RGP lens to correct your vision if you have an unusually high prescription to give you the best optical clarity possible.
Finally, because these lenses are designed to float on top of your tear film, they allow for healthy tear exchange between the cornea and the lens. Your tears carry vital nutrients and molecules responsible for keeping your cornea healthy and free of bacteria. Some custom lens options do not allow for this tear exchange and are considered to be of higher risk. RGP lenses do not carry the same strict follow up schedules that some other lenses require.
The Disadvantages: No lens is perfect!
The biggest disadvantage to RGP lenses is their comfort. Most patients do fine after an initial adaptation period of 1-2 weeks. But, if you’re completely new to them, that first week can be pretty tough. Some patients say, “I feel like I have rocks or sand in my eyes and I want to rip them out!” Others just shrug and say, “I can feel them, but they don’t hurt.” Some people adapt easily, others don’t adapt at all. There’s no way to predict your experience with these lenses as every patient, every prescription, and every cornea is unique.
Some patients might consider the cleaning regiment to be a disadvantage as well. The solutions required to care for your lenses properly can be more costly than traditional saline. The solutions for RGP lenses are often more caustic and more care is required when using them.