subject: Which contact lenses to be purchased? [print this page] Contact lenses are proved some of the best alternatives for people with certain vision problems in addition to glasses. They can offer wearers great freedom and convenience. Of course, these lenses should also be maintained very carefully. However, different people may be in need of different lenses. Here is a simple introduction about some of the most popular lenses in the market, hoping it let people know more about these lenses before buying them.
People who are suffering from nearsightedness, farsightedness and astigmatism can use toric lenses. They are functionally the same as cylindrical lenses. If people's two eyes suffer from different problems, they should choose different lenses for each eye. For example, toric lens is for astigmatism and spherical lens for other regular problems. Comparatively speaking, toric lenses are different from regular lenses in many aspects. They have a top and bottom, which vary a lot in design; they can rectify cylindrical and spherical aberration; they can be worn for longer time, etc.
People who want to have their eyes enjoy more gas can wear RGP (rigid gas permeable lenses). Made from special materials, these durable lenses can let through sufficient oxygen.
People who want to wear extended lenses can choose vial lenses. These lenses can be worn for very long time, several months or to a year and can let oxygen through. There are usually soft lenses and rigid lenses of this series. These lenses are convenient to maintain and can be worn for a very long time.
Therefore, people should know what their needs are and what kind of lenses they need before buying. However, it is still essential to consult with eye doctor before buying.
