Contact Lenses Overview

Gain a better understanding of the various types of contact lenses available today. Compare differences between each to help you decide which type is best for you.

What contact lenses can do for you

Contact Lenses are the perfect solution for people with vision problems who do not wish to have surgery and do not like the feel or appearance of eyeglasses. Millions of people wear these little discs that fit right on your eye and give you crisp, clear vision. Contact lenses will not change your appearance unless you choose color contact lenses or specialty contacts to give your eyes a new color or a different look. The majority of people are able to wear contacts, but some people cannot due to their particular susceptibility to eye infections or extra sensitive eyes.

Contact Lenses Overview

The first step in getting contacts is to visit your ophthalmologist or optometrist. They will measure your eyes and find the right contact to fit properly and comfortably. If you are new to wearing contacts and afraid of touching your eye, your doctor can help you get used to putting your contact lenses in and taking them out. You can read more about this topic in our article Fears of Newcomers to Contact Lenses. After some time even the most sensitive people will be able to wear lenses with ease. The doctor will also advise you on the different types of contact lenses and how to properly take care of them. One of the first things you will learn is how to tell if your contact lens is flipped inside-out. It is easy to tell when contact lenses are inside out because of the slight discomfort caused by the contact not fitting properly onto the eye. Another way to tell without even placing the contacts onto your eyes is to hold the bottom curve of the lens on one finger. If you have a perfect half circle without any edges sticking out then the contacts are fine. If it is a half-circle shape with the edges sticking out, then the contact lens is flipped inside-out.

Normal contact lens Inside out contact lens
Normal Contact Inside out contact

Types of Contact Lenses

Hard Contact lenses

There are very few hard-contact lens wearers today due to improvements in other types of lenses. Hard contact lenses are made of hard plastic; some are gas-permeable and some are not. They provide clear vision and last a long time (five to ten years) but are harder to adjust to than newer types of lenses such as soft disposable lenses. They may be harder to insert and take out, but they do correct most vision problems. Non-gas permeable lenses do not allow oxygen to reach the cornea. These lenses can only be worn for a limited time because major damage can occur to the eye if no oxygen passes through to the cornea. Gas permeable lenses offer the same advantages, but also allow longer wearing time and greater comfort since oxygen can flow easily through them.

Daily wear soft contact lenses

Daily wear soft lenses are made of flexible polymer-plastic materials. These lenses allow oxygen to pass through to the cornea, provide great comfort, and are easy to adjust to. They can also be worn for longer periods of time and can come in different colors. Some drawbacks of daily wear contact lenses include a shorter life span, inability to correct some vision problems, and lack of durability.

Extended wear lenses

Extended wear lenses are soft lenses that have been made to be worn for longer periods of time (about seven days) without removal and cleaning. These lenses allow more oxygen to pass through to the cornea. Ciba Air Optix® NIGHT & DAY™ Aqua lenses, for example, allow for thirty days of continuous wear. These lenses are made from silicone hydrogel that allows up to six times more oxygen to pass through than disposable lenses. They also do not dry up as much as ordinary soft contact lenses and have a bio-compatible lens surface that discourages protein and bacteria buildup.

Rigid gas-permeable (RGP) lenses

Rigid gas-permeable lenses are similar to hard contact lenses, but some are made of better material that allows more oxygen to pass through than even soft contacts. They are made of hard plastic that gives crisp vision and corrects most vision problems. They are durable and have a longer life-span than soft contact lenses. Like hard lenses, they do require some time to get used to and are not recommended for highly physical activities.

Disposable lenses

Disposable lenses are designed to be worn for a limited time and then discarded. Disposables have a replacement schedule that can range from one day to three months, depending on how well they are taken care of and on the environment in which they are worn. Usually the replacement schedule is two weeks. Daily wear disposable lenses should be taken out daily and cleaned until the replacement schedule. Extended wear disposable lenses can be worn overnight, but should still be cleaned and disinfected to prevent eye problems. Disposable lenses are more comfortable and easier to maintain because they are used until it is time to replace them and then thrown away.

Buying Contact Lenses

In the United States, the FDA requires you to have a prescription before buying contact lenses. The reason for this is due to the problems contact lenses can cause if they do not fit your eyes properly. According to the FDA, contact lenses are medical devices and therefore should only be used under the direction of an eye care professional. If you have a prescription, you can buy contact lenses from a variety of places including your eye doctor, optical chains, mass warehouses (Costco, Sam’s Club, etc.), and online retailers. Be wary of contact lens dealers who are willing to sell you lenses without a prescription. These dealers are not concerned with your overall eye health and should be avoided and reported to the FDA. If you want to file a complaint about illegal distribution of contact lenses go here. Learn more about the best places to buy contact lenses.

Contact Lenses: Problem Areas

Wearing contact lenses for a long period of time may cause blurry vision, pain, and redness due to the lack of oxygen passing through to the cornea. A lack of oxygen can also change the shape of your cornea and may result in uneven vision. Improper cleaning of contact lenses can result in bacterial infections which can lead to other eye diseases. Therefore it is a good rule of thumb to wear contact lenses for a limited time, clean and disinfect lenses properly, and schedule routine check-ups.

Contact Lenses – Cleaning and Disinfecting

Always follow the instructions given to you by your eye doctor when cleaning your lenses. Some general guidelines should be followed for all lens types. Always wash your hands before removing or inserting the lens. Always use quality lens-care products and try to clean lenses as often as possible to remove buildup. Always follow guidelines in the instructions for minimum soaking time before wearing your lenses again. Always clean the lens case with solution and replace it at least every three months. Learn more about cleaning and disinfecting your contact lenses here.

Common Brands of Contact Lenses

  • Acuvue
  • Air Optix
  • AquaComfort
  • Biofinity
  • Biomedics
  • Focus
  • Frequency 55
  • FreshLook
  • Proclear
  • PureVision
  • SofLens

Talking to Your Eye Doctor

Here are some questions to ask your eye doctor about contact lenses:

  • How often should I clean my lenses?
  • Which lens solution should I be using?
  • What should I do if I want to switch my solution?
  • How much will my contact lenses cost over the course of a year?
  • Where else can I buy lenses?
  • Can you show me the correct way to insert and remove my lenses?
  • What should I do if I am struggling to adjust to my new lenses?
  • Why shouldn’t I be afraid of wearing contacts?
  • Are contact lenses safe for children and teens to use?
  • What should I do if I mix up my right and left lenses?
  • For my next appointment, should I bring in my lenses, solutions, and storage case?
References:
  • J. Weizer, MD; J. Stein, MD, MS “Reader’s Digest Guide to Eye Care” (Quantum Publishing, Ltd. 2009) 121-126
  • J. Anshel, MD “Smart Medicine for Your Eyes” (SquareOne Publishers 2011) 223-260
  • The Merck Manual Home Edition of Medical Information 2006
This article was last updated on 03/2013