In 2008, over 34 million Americans used contact lenses as their primary form of vision correction, and every year, new lens options are introduced into the marketplace. Today’s contacts lenses correct myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and even presbyopia. In fact, given the increasing number of contact lens options available, more and more people are now eligible to wear contacts, even if in the past they were told they could not.
There are many reasons why people choose to wear contacts. Some find them more convenient than glasses; others enjoy the full field of unobstructed view; and many prefer the look of contacts to glasses. No matter the reason, contact lenses should accomplish three things: correct vision, fit properly and accommodate a patient’s needs and lifestyle.
Contact lenses are classified both by the type of lens material used and the wearing schedule. Options include:
- Soft daily wear contact lenses
- Rigid gas permeable (RGP) contact lenses
- Contact lenses to correct astigmatism
- Extended wear contact lenses
- Disposable or planned replacement contact lenses
- Specialty contact lenses
There are thousands of possible combinations available, but regardless the type of contact lenses a patient is interested in, a thorough examination, lens fitting and a valid prescription are required.
Learn more about the different types of contact lenses available:
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 better maintain its health and clarity. Because they are thin and flexible, soft contact lenses are easier to adapt to and more comfortable than rigid gas permeable contact lenses. A newer type of soft lens is made of a silicone hydrogel material, allowing an even greater amount of oxygen to reach the cornea. Soft daily contact lenses require careful cleaning and disinfection as they tend to attract protein deposits from tear film.
Rigid Gas Permeable (RGP) Contact Lenses
When compared to soft lenses, Rigid Gas Permeable Contact Lenses (RGP’s) are more durable, more resistant to deposit buildup and generally provide clearer, crisper vision. RGP’s tend to be less expensive over the life of the lens since they last longer than soft lenses. RGP’s are also easier to handle and less likely to tear, although they are not as comfortable as soft lenses and may take longer for the wearer to adapt to.
Contact Lenses for Astigmatism
People with astigmatism have an unequal curvature of the cornea resembling a football rather than the basketball shape of a normal cornea. Contact lenses that correct the accompanying visual disturbances caused by astigmatism are called toric lenses. Toric lenses are readily available in both soft and rigid gas permeable prescriptions, however, they require greater fitting expertise in order to obtain the most precise vision.
Extended Wear Contact Lenses
There are a number of FDA approved extended wear contact lenses that can be worn overnight, from six nights up to 30 days. Most extended wear lenses are soft, although there are also several rigid gas permeable lenses FDA approved for extended wear.
Soft extended wear lenses are made of a highly permeable hydrogel, or water-containing plastic that allow oxygen to pass through to the cornea. Rigid gas permeable lenses designed and approved for overnight wear are typically made of fluoro-silicone acrylic materials, which do not contain water, but due to the nature of the plastic, are quite permeable to oxygen. How long someone is able to wear the contact lenses depends on the lens type and the specific recommendations of his or her eye care provider. In general, it is important that the eyes rest without lenses for at least one night following each scheduled removal.
Disposable or Planned Replacement Contact Lenses
Disposable and planned replacement contact lenses are the most popular type of lenses prescribed today. They are healthier for the eye than traditional contact lenses and more comfortable for the wearer.
In the past, contact lenses were generally worn for six months or more and required frequent cleaning and disinfecting. Using disposable, or planned replacement contacts, patients wear the lenses for a specified amount of time, discard the lenses and then replace them with fresh ones. The less time a lens remains in the eye, the less risk of buildup on the lens and eye infections.
Disposable and planned replacement contact lenses are available for daily or extended wear and are generally used anywhere from one day to one month. Many of today’s lens wearers opt for daily disposable contacts, mainly for the convenience. Since lenses are worn once and discarded, there is no need to buy solution and cleaners. The cost of daily contacts has also come down in recent years, making it a much more affordable option.