Contacts, or contact lenses, are small, thin optical lenses placed directly upon the cornea of the eyes. Contact lenses have been used to correct poor vision for more than 150 years, and they are worn by more than 15 million people worldwide. Most contact lenses are available over the counter, but some may need a prescription in order to obtain them. The best time to get your contact lenses changed is during your eye exam. Here are some details about how contact lenses work and what you should expect when you visit your eye doctor for the first time.
There are two basic types of contact lenses – rigid gas permeable contact lenses (RGP contact lenses) and soft contact lenses (SCOP contact lenses). RGP lenses contain a gas permeable layer that reduces or completely removes the amount of gas present on the eye surface. This allows for more oxygen to be present on the eye surface which provides many benefits, including the ability to heal eye infections. However, RGP contact lenses are not suitable for everyone and must be prescribed by a doctor.
Soft contact lenses contain a silicone hydrogel layer which serves the same purpose as the RGP layer in RGP contact lenses. But the silicone hydrogel layer allows for increased oxygen flow onto the cornea. This increased oxygen flow allows for more oxygen to reach the eye, which improves vision. Some of these soft contact lenses have a small gas permeable layer which is not used for vision correction. These lenses can also be prescribed by a doctor.
Once you visit your eye doctor and have decided to use contact lenses, he will prescribe you either a hard or soft contact lens. The size of contact lenses that you are prescribed will depend on many factors including the thickness of your cornea, where you will be wearing them, and the shape of your eye. Once you receive your prescription, you will need to purchase your contact lenses. Contact lenses that are prescribed by an eye doctor can be very expensive, but they can also be very good quality. If you are interested in buying your contact lenses online, there are many reputable online retailers that offer competitive prices.
You should be very careful when purchasing contact lenses online. It is best to purchase from an accredited eye care website. There are some websites that are fraudulent and sell contact lenses that do not work and do not fit. Do your homework and research the different sites that sell contact lenses. Most reputable websites have customer testimonials so you can determine the reputation of a site before you make your purchase.
Both hard and soft contact lenses are great choices. The decision that you make will largely depend on your personal preferences. If you find that the traditional rigid gas permeable lenses are comfortable and easy to wear, then you will most likely want to purchase these contact lenses. If you prefer a softer contact lens that gives you a natural look, then soft contact lenses may be the better option for you.