People can now purchase extended contact lenses of various types for different needs. Some of them can be slept in and others must be removed everyday. And these lenses can be categorized into different groups according to different criteria. For example, soft contact lenses and rigid oxygen permeable lenses are lenses judged from the perspective of composition. The former can offer sufficient moisture for eyes and the later can let through enough oxygen for eyes. Some of these extended lenses can be used for very long time if properly maintained.
However, many people will be confused on how to maintain these extended lenses. For example, some of them do not know when to discard these lenses after wearing for sometime and how long these lenses can be worn each day. Many people have even made many other mistakes in using these lenses and their eyes have suffered greatly.
On the whole, extended eye wear are nice options for people with dry eyes. These lenses are made from special polymer that can offer sufficient moisture for eyes. This is also why most extended lenses can offer wearers great comfort and freshness.
In most cases, it is not a good idea to sleep in extended lenses. This is because eye can not get sufficient oxygen and blood vessels on them will become swollen. And the result might be corneal infection. Other complications may also appear in this situation.
And now, many problems in conventional lenses can be well resolved with some new productions in the field. These new lenses are made from silicone hydro gel, a kind of new and special materials for lenses. These lenses can ensure that more oxygen can be let through. Therefore, these lenses can be worn for very long time with great comfort and freshness.
If you want to know more about contact lenses knowledge, then feel free to visit http://vision.firmoo.com/contact-lenses