Rigid gas permeable contact lenses are the alternative type of contact lens to soft contact lenses. They were initially developed in the 1970s and although the market for these types of lenses is smaller they continue to be made today. Even rigid lenses have a certain amount of “give” to them, which of course makes them comfortable to wear and safe to use on the surface of a highly sensitive organ like the eye.
Rigid gas permeable lenses, or RGP lenses in their abbreviated form, are made from oxygen-permeable polymers and as this would indicate, one of the crucial facts about these lenses is that they are easily permeable by oxygen, which is a vital feature that keeps the eye healthier and less prone to infections. This is one way in which these types of lenses still exceed the performance of soft contact lenses.
Advantages of rigid contact lenses
Rigid contact lenses have a unique set of advantages which sets them apart from other types of lenses. One major benefit of rigid contact lenses is that they provide extremely crisp, clear and sharp vision – some wearers of soft contact lenses do not always quite get the precise visual acuity that RGP lenses offer. This is especially true for those who need vision correction for astigmatism and presbyopia.
Rigid gas permeable contact lenses likewise have great versatility in the eye conditions they can be used to correct. There is practically no eye condition for which corrective RGP lenses cannot be made. While soft contacts can treat most ocular problems, their rigid counterparts can even be used to correct problem cases.
The high durability of rigid contact lenses means they seldom need to be replaced, and it is easy to clean and care for them. With proper care, regular cleaning, and assuming that your vision correction needs do not change over time, RGP lenses can last for up to three years before replacement becomes necessary. They are comfortable for most people who wear them, though they take longer for the wearer to get used to and have to be worn regularly.
Finally, RGP contact lenses allow a lot of oxygen to pass through to the eye, which is good for eye health and can prevent eye infections. The high oxygen permeability of these types of lenses is also why they can be an alternative for lens wearers who are interested in extended wear contact lenses, meaning they can be worn overnight and for extended periods of time. If you are interested in extended wear contact lenses it is worth talking to your optician first to find out what options are available.
Disadvantages of rigid contact lenses
Though rigid contact lenses have many advantages, they are not perfectly suited to every situation or every user, either. For example, although they are easy to insert, they are less secure than soft contact lenses and have been known to fall out during vigorous physical activity. Since they do not conform to the eye’s surface, rigid contact lenses sometimes collect irritating debris under the lens, which can pose a risk of corneal abrasion.
Their biggest drawback, however, is that they need to be worn constantly to maintain the eye’s adaptation to them. Therefore, if these lenses are not worn for some time, the eyes have to re-adapt to them again in order for them to feel comfortable again. Although, this is more an issue of discipline and lifestyle, so if you only want to wear contacts now and again for certain times or events, then maybe RGP lenses are not for you.
There has been a clear decline in fittings of RGP lenses at the expense of soft contact lenses. However, there are still some countries where the use of rigid lenses remains strong, such as in Japan, the Netherlands, New Zealand and Portugal. Currently, it would appear that RGP lenses will continue to serve a smaller more niche market as many opticians are still of the opinion that RGP lenses provide better visual acuity for astigmatism, for example.