Types of Contacts
There are two major categories of contact lenses: soft contact lenses and Rigid Gas Permeable (RGP) contact lenses. Regardless of the type of contacts that you are interested in, they require a thorough examination and fitting-and a valid prescription. Within these two major categories are a number of types of lenses for solving different vision problems. These include:
- Soft Daily Wear Contact Lenses
- Rigid Gas Permeable (RGP) Contact Lenses
- Contact Lenses for Astigmatism
- Extended Wear Contact Lenses
- Disposable or Planned Replacement Contact Lenses
- Specialty Contact Lenses such as: Orthokeratology (Ortho-K) and colored Contact Lenses
Soft Daily Wear Contact Lenses
Soft daily wear contact lenses are made of soft water containing, flexible plastics, called “hydrogels”, that allow oxygen to pass to the cornea to maintain its health and clarity. Because they are soft, thin and flexible, soft contact lenses are easier to adapt to and more comfortable than Rigid Gas Permeable (RGP) contact lenses. A newer type of soft contact lens is made of a “silicone hydrogel” material that allows an even greater amount of oxygen to reach the cornea than any previous soft contact lens, adding additional safety. Soft daily wear contact lenses require careful cleaning and disinfection, as they tend to attract deposits of protein from your tear film.
Rigid Gas Permeable (RGP) Contact Lenses
Rigid Gas Permeable contact lenses (RGPs) are more durable and resistant to deposit buildup, and generally give clearer, crisper vision. They tend to be less expensive over the life of the lens since they last longer than soft contact lenses. They are easier to handle and less likely to tear. However, they are not as comfortable as soft contacts and it may take a several weeks of adaptation in order to get used to wearing RGPs as compared to only a few days for soft contacts.
People who have astigmatism, usually have an unequal curvature of their cornea so that it is shaped more like a football than a basketball. Contact lenses that correct astigmatism are called “toric” lenses. Toric lenses are readily available in both soft contacts and rigid gas permeable contact lens prescriptions. Toric contact lenses require a greater degree of fitting expertise in order to obtain the most precise vision.
Extended Wear Contact Lenses
There are a number of extended wear contact lenses that are available and FDA approved to be worn overnight or in some cases as long as one to six nights or up to 30 days. Most Extended Wear Contact Lenses are soft contact lenses although there are several Rigid Gas Permeable contact lens materials that are FDA approved for extended wear. Soft extended wear lenses are made of highly oxygen permeable hydrogel or “water containing” plastics that allow a great deal of oxygen to pass through to the cornea. Currently the highest degree of oxygen permeability is provided by silicone hydrogel materials. The Rigid Gas Permeable lenses that are designed and approved for overnight wear are typically made of “fluorosilicone” acrylic materials, which do not contain water, but due to the nature of the plastic, are quite permeable to oxygen. How long you are able to wear your contact lenses will depend on the lens type and the specific recommendations of your Heights Eyecare Optometrist based on your contact lens examination, contact lens fitting and the evaluation of your tolerance for overnight wear. In general, it is important for your eyes to have a rest without lenses for at least one night following each scheduled removal. Thus, you must have a pair of backup eyeglasses even if you wear extended wear contact lenses or contact lenses of any type.
Disposable or Planned Replacement Contact Lenses
Today, most daily wear and extended wear soft contact lenses are prescribed with a very specific “planned replacement schedule”. That is, the prescribing eye doctor will give you instructions on how frequently to replace your lenses based on your tear film, how often you may be removing the lenses and how quickly you soil the lenses, even after cleaning and disinfection. True “disposable” contact lenses are worn only once and then discarded. In order to have a “daily wear disposable schedule”, a brand new pair of lenses is used each day.
Patients need to be cautious if they do not have their contact lens prescriptions filled at Heights Eyecare. Contact lens sellers refer to some soft contact lenses as “disposable”, but actually, they are for frequent/planned replacement. With extended wear lenses, the lenses may be worn continuously for the prescribed wearing period (for example, 7 days to 30 days) and then thrown away. If you are wearing your lenses on a planned replacement basis or even an extended wear basis, when you remove your lenses, ALWAYS make sure to clean and disinfect them properly before reinserting them. This is necessary in order to protect the health of your eyes and allow you to continue to wear your contacts comfortably and safely.
Specialty Contact lenses
At Heights Eyecare, the vast majority of contact lenses prescribed fall into the categories as described so far. We do prescribe contact lenses for some special purposes for those patients requesting these types of fittings and contact lenses:
Keratoconus, Post-Surgical and Hard to fit corneas
Some people have corneas that are very irregular shaped and do not allow for clear vision through glasses. These types of corneas usually need some special attention and a specially designed lens that can either reshape the cornea or perhaps vault over the imperfect front surface of the eye. At Heights Eyecare we have several specialty fitting sets that are used to diagnostically treat the front surface of the eye and allow for clearer vision. We also have a corneal topographer that is used to help aid in the fitting of these complicated lenses. A lot of time and care goes into providing a lens that will maintain proper health, comfort and vision in these cases.
Colored Contact Lenses
A type of specialty lens contact lens that has become popular among people who don’t even have a need for vision correction are contacts that have the sole purpose of changing the appearance of your eyes. These are sometimes called “Plano”, “Zero-Powered” or “Non-Corrective” lenses. Wearers of these contact lenses can temporarily change a brown eyes to blue.
EVEN THOUGH THESE COLORED LENSES MAY NOT CORRECT VISION, THEY'RE A MEDICAL DEVICE AND THE FDA STRICTLY REGULATES THEM (This is because, even with correction, they pose the identical risks to patients that “regular’ contact lenses pose. These include:
- Conjunctivitis or Pink Eye
- Corneal Abrasions
- Corneal Ulcers
- Vision Impairment
Many patients are simply unaware of the need for proper fitting and prescription of these lenses and have purchased decorative contact lenses from beauty salons, record stores, video stores, flea markets, convenience stores, beach shops and the Internet. Buying contact lenses without a prescription is dangerous!
Please do not substitute, disregard or delay seeking professional medical advice based on this program and call your doctor or emergency medical services immediately for any medical emergency!