Types of Contact Lenses
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, every patient requires 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
- Multifocal (Presbyopic) Contact Lenses
- Specialty Contact Lenses
- Decorative Non Prescription Contact Lenses
- Keratoconus Contact Lenses
- Contact Lens Safety and Risks
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 several weeks of adaptation in order to get used to wearing RGPs as compared to only a few days for soft contacts.
Contact Lenses for Astigmatism
People who have astigmatism usually have an unequal curvature of their cornea so that it is shaped more like a football than a baseball. 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. They also 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, 1 week, or even 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 similar in composition as Soft Daily Wear lenses. Rigid Gas Permeable (RGP) 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 Spector Eye Care doctor 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 very specific instructions on how frequently to replace them based on your tear film, how often you may be removing them and how quickly you soil them 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 Spector Eye Care. 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.
Multifocal (Presbyopic) Contact Lenses
Multifocal Contact Lenses have become increasingly popular as a greater number of patients enter their 40′s and wish to continue enjoying the benefits of Contact Lens wear without being dependent on eyeglasses or reading glasses for close vision throughout their day. Multifocal Contact Lenses are available in a number of different designs, materials and prescriptions that are useful for successfully fitting a wide range of patients and their various far, intermediate and near vision correction needs. The key to success is a careful thorough examination and fitting along with helping each patient understand their actual vision correction needs.
Specialty Contact Lenses
At Spector Eye Care, 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:
Orthokeratology (Ortho-K) Contact Lenses
Orthokeratology (also called Ortho-K) is a technique that uses special contact lenses to reshape your eyes while you sleep. This allows you to have better vision during the day while not wearing corrective lenses. The effects of Orthokeratology are only temporary, so the lenses must be worn often to maintain good vision. For many patients, Orthokeratology requires wearing lenses nightly, though it varies from person to person. Some patients will only need to wear their contact lenses 3 to 4 times per week.
Ortho-K is generally only for people with mild-to-moderate myopia (nearsightedness) or astigmatism including patients with up to six (6.00D) diopters of myopia or one and three quarters (1.75D) diopters of astigmatism and who might not otherwise be good candidates for Laser Eye Surgery such as LASIK. The ideal candidates are those with four (4) diopters of myopia or less.
Like Laser Vision Correction, Orthokeratology flattens the cornea of myopic patients, enabling light rays entering the eye to focus properly on the retina. The lenses are rigid gas-permeable (RGP), snug fitting and somewhat flattened in the center to put pressure on the cornea and change its shape. Ortho-K is generally a gradual process, and may require a series of different lenses, though that will depend on the specifics of the patient and the type of lenses being prescribed. Orthokeratology may seem like a strange choice, given the popularity of procedures such as LASIK, which enable patients to be considerably less dependent on or even eliminate contact lenses for distance vision. However, not everyone is eligible for LASIK Surgery such as those under 21 years of age, those with dry eyes or thin corneas, and some other eye or health issues that make them poor candidates for Laser Vision Correction.
Decorative Non Prescription Contact Lenses
A type of specialty 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 brown eyes to blue and can even create different themes such as Halloween or Dracula by modifying the eye’s appearance.
EVEN THOUGH THESE DECORATIVE LENSES DO NOT CORRECT VISION, THEY ARE 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.
Keratoconus Contact Lenses
Keratoconus is a progressive thinning of the cornea that results in the shape of the cornea becoming “cone like”. This irregular shape can cause a significant distortion of vision that is not well corrected, or possibly corrected at all by eyeglasses. In fact, in most cases of Keratoconus with irregularly shaped corneas neither eyeglasses nor soft contact lenses alone provide an adequate vision correction option. The best contact lens correction for Keratoconus is achieved by using a system of specially fit and designed Rigid Gas Permeable (RGP) Contact Lenses that may have a) unique interior curves to vault over the protruding corneal area, b) large overall diameters, c) a design that is “semi-scleral” and fits beyond the cornea diameter, d) a gas permeable center contact lens with a soft lens skirt attached to the outside, called a “hybrid” design or even e) a carefully selected soft lens is placed on the eye, then a specially fit gas permeable lens rests on top of the soft lens, called a “piggyback” design.
Contact Lens Safety and Risks
If you are considering getting contact lenses of ANY type, the eye doctors at Spector Eye Care recommend the following:
Having a thorough eye exam from a licensed Optometrist or Ophthalmologist. Having a careful fitting and getting a valid prescription that includes the brand and complete set of lens parameters. Purchasing the lenses from either Spector Eye Care directly, an eye care professional or from a vendor who requires that you provide prescription information for the lenses Carefully following directions given to you for cleaning, disinfection, and wearing the lenses.
Visiting the Optometrist or Ophthalmologist who initially prescribed your contacts for follow-up eye exams in order to make sure they are fitting properly.
Most people who need vision correction are able to wear contact lenses safely and comfortably, but there are some exceptions. Some of the conditions that might keep you from wearing contact lenses are: frequent eye infections, severe allergies, dry eyes or an inadequate tear film, a work environment that is very dusty or dirty and inability to handle and care for the lenses properly.
Contact Lens Care & Safety
There are a number of good hygiene practices that will help you to wear your contacts safely and comfortably. Please take time to read and then practice the following care principles:
- Your contact lenses must be properly cleaned and disinfected each time you remove them in order to kill germs and prevent infections.
- At the time you insert your contact lenses, you should thoroughly rinse the case with warm water and allow it to dry. All contact lens cases need frequent cleaning, including disposable lens cases.
- Never put your contact lens in your mouth and then insert it into your eye.
- Never use homemade cleaning solutions; they have been linked to serious eye infections.
- Do not attempt to sterilize disposable lenses – you must discard them.
- Never mix different brands of solutions
- Any eye drops, even nonprescription ones, can interact with all types of contact lenses.
- Only use the brand of solution prescribed by the Optometrist or Ophthalmologist who fit you or else check with the doctor before changing brands.
- Always wash your hands with soap prior to handling contact lenses or touching your eye.
- Do not share your lenses with someone else.
- Do not take your lenses in and out repeatedly throughout the day.
- Only wear your contacts on the schedule prescribed by your doctor.
- Dispose of your contact lenses at the interval prescribed by your doctor.
Call your Spector Eye Care Doctor If You Experience Any These Symptoms:
- Redness lasting more than one day
- Discharge from your eye
- Blurred Vision
- Unusual Scratchiness