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The development of the contact lens has changed how those with bad vision see the world. At one time hard lenses were the only contact lenses that anyone had access to, but later came the disposable soft lens that required less care and could be thrown away after a certain time period of wear. Now there are many different options available to contact lens wearers based on their requests and the recommendations of their doctors. This allows more people to wear contact lenses than ever before. Many of those who could not wear contacts years ago, because the kind that was being used was not for them, can now wear them with ease.

With their being so many kinds available, the type of contact that is prescribed is dependent upon a person's particular situation. Here are the different types of contact lenses that are available:

1. PMMA lenses, which are also called hard contact lenses are the oldest that are around. Believe it or not they have been around since the 1960s. They are made from polymethyl methacrylate (PMMA). These contacts are very durable, but their disadvantage is the fact that they do not allow oxygen to reach the cornea directly. The oxygen is received in the cornea when the wearer blinks and oxygen-rich tears reach the cornea due to the movement of the lens. They are of low cost, but they are hardly used anymore. However, there are some patients who prefer them.

2. Soft contact lenses are the lenses that are used most often. They are made of plastic and other materials such as silicone. Water is also used in their construction, which makes them soft. They also allow the oxygen to directly reach the cornea. Soft contact lenses are used by 3/4 of the contact wearers in the United States. There are also different types of soft contacts such as:

- Daily disposable lenses that must be thrown away at the end of each day. These are more expensive, but the risk of developing an eye infection is minimal.

- Toric lenses for astigmatism. These contacts are for those who do not have any other eye issue other than astigmatism that must be corrected.

- Extended wear lenses typically last 2-4 weeks. The usage of the 30 day contact started approximately 6 years ago. The risk of infection is higher and they do tend to be somewhat expensive, but the wearer is able to wear the contacts day and night for 30 days without having to take them out.

3. The last type of contact lens is the gas-permeable lens. These are the newer version of the hard lens that are made of silicone and other materials that allows the oxygen to directly reach the cornea. This is why they are called gas permeable.

There are so many advantages to using contact lenses for those who are able to wear one of the above that were described. Of course there are risks such as the hard contact lenses being more likely to scratch the cornea and extended wear contacts causing infection, especially if they are not maintained properly. No matter the type of contact lens a person is wearing, it is important to take care of them they way they are supposed to in order to minimize the risk of infection in the eye. Those who develop frequent eye infections may not be allowed to wear them by their doctor. Even those with severe allergies may be forbidden, but contacts open up a whole new world for those who can wear them because they can see things differently.