Soft Contact Lenses
Soft contact lenses are made of hydrophilic, or “water-loving” polymer. This soft gel-like plastic lets oxygen to pass through the lens and refresh the ocular surface. The oxygen-permeable property keeps the eye surface healthy, allowing for greater wearing comfort and for longer continuous wear. Because the soft contact is comfortable to wear and still provides crisp, stable vision, it is most commonly preferred by contact lens wearers and new wearers adapt easily to them. It is a great choice for those with active lifestyles.
The disadvantages of soft lenses are that the vision obtained from them may not be as sharp as with Rigid Gas Permeable Contact Lenses (RGP) lenses. The lenses tend to soil easily and must be replaced more often. Also, these lenses do not correct all vision problems.
Rigid Gas Permeable Contact Lenses
A less common option, but one with many benefits, is the RGP contact lens. These contacts are made from rigid waterless polymer and also are oxygen permeable. In fact, RGPs transmit more oxygen to the eye than traditional soft contact lenses and therefore promote good ocular health. RGPs are often prescribed to patients with irregular ocular surfaces, patients with astigmatism that can’t be corrected with soft contact lenses, and patients who require bifocal or multifocal lenses.
The rigid lenses correct irregular corneal shapes in patients with astigmatism or keratoconus and smooth out ocular surface irregularities, providing sharp stable vision.
Other benefits of the RGP lenses over the soft lenses are that they are long-lasting, less prone to protein deposit build-up, easier to clean, and generally provide crisper vision than a soft lens. The rigid lenses need an initial adaptation period of a few days to several weeks before they will be comfortable for the wearer, unlike soft lenses that are almost instantly comfortable to wear.
The disadvantages of RGP’s are that they require consistent wear to maintain adaptation. These lenses also tend to slip off the center of the eye more easily than other types of lenses, and it is easier for debris to collect under them. Follow-up care for these lenses requires an office visit.