Contact Lenses: Colored, Soft, Hard, Toric & Bifoc (cont.)
In this Article
Rigid gas permeable lenses, or hard contact lenses, are more rigid than soft contact lenses and therefore more durable. Unlike older versions of hard contact lenses, rigid gas permeable lenses are made with silicone polymers, allowing oxygen to circulate to the cornea of the eye. Compared to soft contact lenses, hard contacts maintain their shape better and offer clearer vision for some types of corrections. They are also easy to take care of and are extremely durable. However, if you are considering this type of hard contact lens, you should know that:
Bifocal contact lenses are designed to give good vision to people who have a presbyopia . These contact lenses work much like bifocal eyeglasses, having two powers on one lens one to correct distant vision and another to correct near vision. Bifocal contact lenses come as both soft and rigid gas permeable lenses.
Toric contact lenses are special lenses for people with astigmatism. Toric contact lenses are made from the same material as other contact lenses and come in soft or rigid gas permeable forms. Like bifocal lenses, toric lenses have two powers, one for the astigmatism and another for nearsightedness or farsightedness if either of these conditions is also present.