Whether you're a first-time wearer or a contact lens veteran, the more you know about your eyes and eye care, the clearer your vision and the healthier your eyes will be.

While many types of contact lenses are available, the type of contacts you use depends on your particular situation. Your eye doctor will be able to help you choose from the following types of lenses:

PMMA lenses: Rigid or "hard" contacts were the first lenses developed and marketed in the 1960's. They are made of a type of plastic called PMMA (polymethyl methacrylate), which is very durable, but does not permit oxygen to pass through the lens. The oxygen needed for good eye health get to the cornea when the lens moves on the eye due to the blinking action. Unfortunately, this movement on the eye, due to blinking, is also what makes this type of lens uncomfortable for most people until the eye acclimates to it.

Gas-permeable lenses: These lenses are also known as "GP or RGP's." They are state-of-the-art lenses made of advanced polymers, such as silicone and fluoropolymers, that are far more comfortable than PMMA and allow oxygen in the air to pass directly through the lens to support good eye health. For this reason, they are called "gas permeable."

CRT Lenses: CRT contact lenses are placed on the eyes just prior to bedtime and removed upon waking. In other words, CRT are ONLY worn while you sleep! During sleep the lenses safely and gently reshape the front surface of the cornea so that when they are removed, you can see clearly for your waking hours. Some CRT wearers report that they can see clearly for a couple days! Many people think of CRT as a temporary and non-surgical from of LASIK. CRT is great for just about everyone with myopia (near sighted ness) and superb for children and for many soft lens wearers that experience eye dryness and discomfort while wearing their contacts during the day. These lenses are manufactured using gas a permeable material that permits a substantial amount of oxygen to pass through the lens while a person sleeps, supporting good eye health.
Added Bonus with CRT: You can see clearly with the lenses on and off so if you get up in the middle of the night you vision will be great.

Soft contact lenses: These lenses are made of plastic materials that incorporate water. The water makes them soft and flexible, as well as allowing oxygen to reach the cornea. About 90% of contact lens wearers in the United States use soft lenses.

Extended wear contact lenses: are designed for continuous overnight wear, typically for 1 to 7 consecutive nights.

Daily disposable lenses: These are soft contact lenses that are only worn for a single day and discarded.

Toric contact lenses: Correct moderate astigmatism. They are available in both rigid and soft materials.

Generally, contacts should be removed at bedtime due to risk of infection and risk of contact lens intolerance unless they are FDA approved for extended wear and your eye doctor belives that your eyes are suitable for overnight wear.