RGP: Rigid Gas Permeable Contacts

Who in their right mind would put a rigid contact lens in their eye with so many soft contacts on the market today? Great question!

In the 1970's, when soft lenses were introduced to the world, the "hard lens" market all but dried up! There were many manufactures that actually went out of business. These "hard lens" materials were just that....hard! They were made of a plastic material, PMMA, poly-methyl-methacrilate. The use of PMMA in the medical field has been common practice since 1945. In addition to their use in hard contacts, PMMA is applied in dental prostheses, hip implants, bone cement, cataract intra-ocular lenses, repair material for cranio-facial surgery as well as many other medical devices.

Because of the initial discomfort and problems with corneal health this material easily gave way to the soft lens of the 1970's.

This inspired research and development of a new rigid material that was more comfortable and more eye friendly. In 1979 a new "gas permeable" material was born. By 1986 the first extended wear rigid gas permeable lens became available for distribution. (Soft lenses by their nature are "gas permeable" that is why rigid lenses have picked up this label.)

"Gas Permeable" means that oxygen and carbon dioxide can actually travel through the contact lens improving comfort and corneal health. It's hard to comprehend just how this happens through a rigid material but the newest gas perm lenses of the 21st century have gas transmissions equal to or sometimes even higher than most soft lenses! In addition to the gas permeability, these lenses are also flexible, adding to their comfort.

Over the last ten years there has been a rebirth of the "rigid" lens market with contact laboratories pouring out all kinds of gas perm designs. Their popularity is actually on the upsurge but still a long way from the popularity of soft lenses.

So, let's get back to our question. What's the advantage of this material over a soft lens? The major reason patients gravitate to RGP's is crispness of vision. There are many RGP wearers who have tried soft lenses but give them up because the vision is not quite as crisp. RGP lenses automatically correct most astigmatism without the need for fancy toric lenses because they provide a perfectly smooth optical surface for light to enter and properly focus in the eye. Where high astigmatism exists, the lens can be ordered to "glove fit" the cornea without having to be concerned with rotation as in a toric soft lens.

One pair of lenses can last a minimum of a year and frequently two or three years! (Why a lot of doctors don't prescribe them!) They are very simple to insert and remove without having to stick one's fingers in the eye. They don't rip like soft lenses. They are more comfortable for patients with dry eye because they don't dry up like some soft lenses do. Tears are able to circulate beneath the lens providing for better eye health.

One of the great benefits of RGP's is in the control of nearsightedness (myopia). Children very rarely have the significant shifts in their RGP prescription as we see with those in glasses. Medically, for those having irregular shaped corneas there is no other material that provides clarity of vision as an RGP. Conditions like keratoconus or other corneal conditions or dystrophies are always treated with RGP's.

The best bifocal designs are made in RGP material because of the excellent optics. They even come in a progressive design. See the section on bifocal contacts for a full explanation of these lenses.

The greatest advancement in RGP's is a hybrid RGP lens called the "Synergeyes hybrid" lens. The main disadvantage of traditional RGP's is that there are some patients that simply cannot tolerate a traditional RGP lens. Synergeyes hybrid lenses have, therefore, become a welcome addition to our array of lenses available for fitting. The lens is more fully described in its own section. Synergeyes is a soft lens with a gas perm center providing the best of both worlds: crisp vision and outstanding comfort. The lens works well with children and adults. It is one of the best on the market for sports. Synergeyes is now available in single vision and bifocal form.

Call Dr. Teles at 410-768-0202 for a free consultation or an appointment.

(By the way, if your answer to "Why would anyone in their right mind wear an RGP?" was "they are left-handed" sorry, that's not the answer we were looking for!)