Contact Lens Basics
If you need vision correction for nearsightedness, farsightedness or astigmatism, contact lenses are a popular and effective option. In the United States, approximately 20% of the population who requires vision correction wears contact lenses. Currently dating back more than 125 years, contacts are presently available in a wide variety of materials and types. As opposed to the situation years ago, nowadays almost everyone can wear contact lenses.
Eyeglasses may be an attractive way to accessorize your outfit and make a fashion statement, yet you may sometimes prefer your appearance without glasses. Contact lenses allow you to have sharp vision without eyeglasses or costly vision surgery. Another benefit of contacts is that they grant a wider field of vision than glasses. This is a major advantage when it comes to playing sports or engaging in hobbies and professions such as photography.
If you are considering wearing contact lenses, you’ll need to schedule an initial eye exam and contact lens evaluation with your eye doctor. In the United States, contacts are regarded as medical devices that require a prescription by an eye care professional (ECP). In order to determine the best lenses for you, your ECP will assess your visual condition, structure of your eye and natural tear production.
Contact lenses are categorized depending upon the following factors:
- Material composition
- How long they can be worn before you have to take them out
- Life span- how long they can be used before you have to toss them and grab a new pair
- Design of the lenses
Material Composition of Contact Lenses
There are four different types of contact lens materials:
Over 90% of contact lenses on the market today are classified as soft lenses. These ultra-comfortable, thin contacts are constructed from gel-like plastics that contain a high percentage of water. They cover the entire cornea of your eye (clear front surface) and it is typically easy to adapt to wearing them.
First introduced in 1971, soft lenses used to be made from hydrogel materials. At present, silicone hydrogel is the most widespread, popular version. They permit a higher quantity of oxygen to reach the eye, which is healthy and comfortable.
Hard, Gas Permeable Lenses
Also called GP or RGP (rigid gas permeable) lenses, these contacts are smaller and made from plastics that have no water. They often provide the advantage of more acute vision, yet it generally takes longer to adapt to wearing them.
The center zone of these lenses is made from rigid gas permeable lenses, and a soft lens material encircles the border. Hybrid lenses thereby provide the best of both worlds – sharp vision from the center and a soft, comfortable border.
Wearing Time for Contact Lenses
The two primary kinds of contact lenses are daily wear and extended wear. Daily wear lenses must be removed on a nightly basis, and extended wear lenses may be worn up to seven days; a few brands of extended wear lenses are approved by the FDA for monthly wear (also known as “continuous wear” lenses). Extended wear lenses are very convenient even if you always remove them before going to sleep, as they are safe and comfortable for napping. Don’t sleep in your lenses unless you’ve discussed this with your doctor, since improper wear times can lead to corneal damage.
Life Span for Contact Lenses
All contact lenses must be discarded after a specified amount of time, even if you care for them well and properly. Soft contact lenses in particular accumulate lens deposits and contamination, which raises your risk of eye infections.
- Daily disposable lenses: the most convenient and healthiest option, these lenses are replaced after one day of wear
- Overnight disposable lenses (kept in your eyes overnight): must be replaced after one week
- Monthly wear lenses: these are discarded after wearing for 30 days.
- Gas permeable contact lenses: these are more resistant to lens deposits and can last up to a year or in many cases even longer with excellent care.
Designs for Contact Lenses
Contact lenses vary depending upon the type of vision correction that is required. The most common design is spherical, which works for nearsightedness, farsightedness and astigmatism. Toric lenses, which come in both soft and GP versions, possess multiple lens powers to correct astigmatism. Bifocal and multifocal lenses utilize a number of zones for different viewing needs, such as near, intermediate and far vision. They are often a good option for presbyopia. Orthokeratology (ortho-k) lenses are designed to reshape the cornea overnight, which corrects daytime vision without a need for eyeglasses or lenses.
Additional Features of Contact Lenses
Colored contacts: Lenses can be worn in color tints that enhance the natural color of your eyes or change your eye color totally. Blue eyes can be made more vibrant, or brown eyes can be altered to green.
Special-effect contacts: These lenses offer an extreme change to the color of your eyes and are generally used for costumes or theatrical effects. You can look like a zombie, an animal, or whatever you envision!
Prosthetic contacts: Disfigurations caused by disease or accidents can be masked by these colored contact lenses. With a medical orientation, prosthetic lenses are generally used to match the appearance of both eyes.
Contact Lenses that are Right for You
To identify the lenses that are ideal for your needs, you must first have a complete eye examination and contact lens evaluation performed by your eye doctor. Your ocular health will be inspected and detailed measurements of your eyes will be taken. Trial lenses will be inserted to check for the best possible and most comfortable fit and vision
After your initial fitting, follow-up visits for contact lenses are important. Your eye doctor will check that the fit is right and that no complications are developing. Your tolerance to contact lenses will be assessed. Sometimes a change in the fit or type of lens is necessary.
Your contact lens prescription will be issued after the fitting process is complete.
Proper Care and Handling of Contact Lenses
It is relatively simple to care for contact lenses. A single, multi-purpose lens solution is generally all that’s required for cleaning, disinfecting and storing your lenses. With daily disposables, routine care is totally eliminated and you can enjoy the feeling of a brand new fresh clean lens every day.
Your eye doctor or contact lens technician will instruct you how to take care of your contact lenses before you leave the office.