Contact Lenses
Contact lenses are the number one choice for many people with vision correction needs. For many, contact lenses provide flexibility and convenience. There are many different lenses available for a variety of needs and preferences. Contact lenses can be used to correct a variety of vision disorders such as Myopia (nearsightedness), Hyperopia (farsightedness), Astigmatism, and Presbyopia (poor focusing with reading material and other near vision tasks).
What are the different types of Contact lenses?
Soft Contact lenses
Soft contact lenses are made of soft, flexible plastics that allow oxygen to pass through to the cornea. Soft Contact lenses may be easier to adjust to and are more comfortable than rigid gas permeable lenses. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eye while you wear your lenses.
Rigid Gas Permeable (RGP) Contact lenses
Rigid gas permeable contact lenses (RGPs) are more durable and resistant to deposit buildup, and generally give a 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 initially as soft contacts and it may take a few weeks to get used to wearing RGPs, compared to several days for soft contacts.
Extended Wear Contact lenses
Extended wear contact lenses are available for overnight or continuous wear ranging from one to six nights or up to 30 days. Extended wear contact lenses are usually soft contact lenses. They are made of flexible plastics that allow oxygen to pass through to the cornea. There are also a very few rigid gas permeable lenses that are designed and approved for overnight wear. Length of continuous wear depends on lens type and your eye care professional’s evaluation of your tolerance for overnight wear. It’s important for the eyes to have a rest without lenses for at least one night following each scheduled removal.
Disposable (Replacement Schedule) Contact lenses
The majority of soft contact lens wearers are prescribed some type of frequent replacement schedule. “Disposable,” as defined by the FDA, means used once and discarded. With a true daily wear disposable schedule, a brand new pair of lenses is used each day.
Some soft contact lenses are referred to as “disposable” by contact lens sellers, 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. When you remove your lenses, make sure to clean and disinfect them properly before reinserting.
Contact Lens Prescription
When you get an eye exam, you have the right to get a copy of your prescription. You can use this prescription at another vendor or to order contact lenses on the Internet, over the phone, or by mail. See Buying Contact lenses.
As defined by the Federal Trade Commission (FTC) regulations, a prescription should contain sufficient information for a seller to completely and accurately fill the prescription. This includes the following items:
- Patient’s name
- Examination date
- Date patient receives prescription after a contact lens fitting (issue date) and expiration date of prescription
- Name, address, phone number and fax number of prescriber
- Power
- Material and/or manufacturer of the prescribed contact lens
- Base curve or appropriate designation of the prescribed contact lens
- Diameter, when appropriate, of the prescribed contact lens
- For a private label contact lens, the name of the manufacturer, trade name of the private label brand, and if applicable, trade name of equivalent brand name.
Is your contact lens prescription current? You should always have a current, valid prescription when you order contact lenses.
If you have not had a check-up in the last one to two years, you may have problems with your eyes that you are not aware of, or your contact lenses may not correct your vision well.
The expiration date for your prescription is currently set by your state. Some require a one-year renewal, some a two-year renewal. If your state has not set a minimum expiration date, Federal regulation sets a one year date unless your eye care professional determines that there’s a medical reason for less than one year.
To be sure that your eyes remain healthy you should not order lenses with a prescription that has expired or stock up on lenses right before the prescription is about to expire. It’s safer to be re-checked by your eye care professional.
What does a valid contact lens prescription include?
As defined by FTC regulations, a prescription should contain sufficient information for a seller to completely and accurately fill the prescription. This includes the following items:
- Patient’s name
- Examination date
- Date patient receives prescription after a contact lens fitting (issue date) and expiration date of prescription
- Name, address, phone number and fax number of prescriber
- Power
- Material and/or manufacturer of the prescribed contact lens
- Base curve or appropriate designation of the prescribed contact lens
- Diameter, when appropriate, of the prescribed contact lens
- For a private label contact lens, the name of the manufacturer, trade name of the private label brand, and if applicable, trade name of equivalent brand name.
Wearing contact lenses puts you at risk of several serious conditions including eye infections and corneal ulcers. These conditions can develop very quickly and can be very serious. In rare cases, these conditions can cause blindness.
You can not determine the seriousness of a problem that develops when you are wearing contact lenses. You have to get help from an eye care professional to determine your problem.
If you experience any symptoms of eye irritation or infection,
remove your lenses immediately and do not put them back in your eyes.
contact your eye care professional right way.
don't throw away your lenses. Store them in your case and take them to your eye care professional. He or she may want to use them to determine the cause of your symptoms.
report serious eye problems associated with your lenses to the FDA’s MedWatch reporting program.
Symptoms of Eye Irritation or Infection
- Discomfort
- Excess tearing or other discharge
- Unusual sensitivity to light
- Itching, burning, or gritty feelings
- Unusual redness
- Blurred vision
- Swelling
- Pain
Other risks of contact lenses include
- Pink eye (conjunctivitis)
- Corneal abrasions
- Eye irritation
Credit: National Institute of Health.