If you have been wearing contact lenses for a while, you probably started out with hard contact lenses. You would have been advised to take extremely good care of them, washing them regularly every night and in return, your lenses would have lasted for years. However, things have changed dramatically on the contact lenses frontier and new developments have meant there are now safer and easier ways to wear contact lenses than ever before.
The old hard contact lenses were made of a material called PMMA (Polymethylmethacrylate), which is a kind of stiff plastic that can be worn in the eye. The main advantages of hard contact lenses were that they were extremely durable and offered almost perfect vision correction. However, they also had some serious limitations. First, because they were so rigid, users never felt quite comfortable wearing hard contact lenses in their eyes. Secondly and more importantly, the material never allowed oxygen to reach the cornea easily. This prevented the eye from breathing easily and the cornea would swell and cloud up the vision.
Repeated complaints of discomfort caused the makers of hard contact lenses to redesign their contact lenses. And the much-improved rigid gas permeable contact lenses were designed.
Rigid Gas Permeable (RGP) Contact Lenses:
A rigid gas permeable contact lens has a self-explanatory name. These contact lenses too are made essentially from a rigid waterless plastic that can be placed in one's eye. The one benefit it offers over the hard contact lenses - oxygen permeability or the ability to allow oxygen to reach the cornea. In fact these lenses allow almost eight times more oxygen to pass through than soft lenses.
A gas permeable lens or RGP lens as it is known has a more rigid surface. This allows the user to have an absolutely clear vision throughout the day. As the RGP lens contains no water, it does not require any moisture to maintain the shape of the lens. Even supposing your eyes get dry during the day, it will not affect your vision. This problem of dry eyes is more marked in soft contact lenses, which need a certain amount of moisture to provide clear vision.
Washing and cleaning rigid gas permeable contact lenses is much more efficient and if you would like them extra clean; your eye care professional can give them a good polish. Every rigid gas permeable contact lens is carefully and individually designed for the users eye including how much of oxygen permeability and moisture is needed.
It is small wonder that RGP lens wearers are some of the most satisfied customers in the market.
The advantage of having a custom designed rigid gas permeable lens is that they can fit anyone no matter what other vision problems they had or are currently having. These include irregular astigmatism, presbyopia, or post lasik.
It is no surprise then, that in the debate between traditional hard lenses and rigid gas permeable lenses, the RGP lenses have been winning hands down. See what you think.