what i need to know about contact lenses

Contact lens basics: Types of contact lenses and more

Contact lenses are an excellent choice for nearly anyone who needs vision correction and doesn't want to article of clothing eyeglasses full time or undergo LASIK surgery.

Unsure almost contact lenses? This article will detail contact lens materials, contact lens designs and features and even new contact lens formats.

For instance, the kickoff light-adaptive contact lenses, Acuvue Oasys with Transitions, debuted in the United States in 2019, and contact lenses embedded with antibiotics are in the works. (See our contact lens news page for the latest in contact lenses.)

Here are the nuts y'all should know about contact lenses before seeing your eye doctor if you are interested in wearing contacts.

Contact Lens Materials

The commencement pick when considering contact lenses is which lens textile will best satisfy your needs. There are five types of contact lenses, based on type of lens fabric they are made of:

Contact Lens Material

• Soft lenses are made from gel-similar, water-containing plastics chosen hydrogels. These lenses are very sparse and pliable and accommodate to the front surface of the eye. Introduced in the early on 1970s, hydrogel lenses made contact lens wear much more pop considering they typically are immediately comfortable. The only alternative at the fourth dimension was hard contact lenses fabricated of PMMA plastic (come across beneath). PMMA lenses typically took weeks to adapt to and many people couldn't wear them successfully.

• Silicone hydrogel lenses are an advanced blazon of soft contact lenses that are more porous than regular hydrogel lenses and allow fifty-fifty more oxygen to reach the cornea. Introduced in 2002, silicone hydrogel contact lenses are at present the most popular lenses prescribed in the U.s..

• Gas permeable lenses — too called GP or RGP lenses — are rigid contact lenses that look and feel like PMMA lenses (encounter below) simply are porous and allow oxygen to laissez passer through them. Because they are permeable to oxygen, GP lenses can be fit closer to the eye than PMMA lenses, making them more than comfortable than conventional hard lenses. Since their introduction in 1978, gas permeable contact lenses have substantially replaced nonporous PMMA contact lenses. GP contacts often provide sharper vision than soft and silicone hydrogel contacts — particularly if you have astigmatism. It usually takes some time for your eyes to adapt to gas permeable lenses when you beginning start wearing them, but after this initial accommodation menstruation, about people find GP lenses are equally comfy equally hydrogel lenses.

• Hybrid contact lenses are designed to provide wearing comfort that rivals soft or silicone hydrogel lenses, combined with the crystal-clear optics of gas permeable lenses. Hybrid lenses have a rigid gas permeable central zone, surrounded by a "brim" of hydrogel or silicone hydrogel material. Despite these features, only a small per centum of people in the U.South. wear hybrid contact lenses, perhaps because these lenses are more difficult to fit and are more than expensive to supplant than soft and silicone hydrogel lenses.

• PMMA lenses are fabricated from a transparent rigid plastic textile chosen polymethyl methacrylate (PMMA), which besides is used as a substitute for glass in shatterproof windows and is sold under the trademarks Lucite, Perspex and Plexiglas. PMMA lenses have excellent eyes, but they do not transmit oxygen to the eye and can exist difficult to conform to. These (at present old-fashioned) "hard contacts" have virtually been replaced by GP lenses and are rarely prescribed today.

In 2017, 64 per centum of contact lenses prescribed in the U.Due south. were silicone hydrogel lenses, followed past soft (hydrogel) lenses (22 percent), gas permeable lenses (11 percentage), hybrid lenses (two percent) and PMMA lenses (1 percent).

LEARN MORE about the proper care of your contact lenses .

Contact Lens Wearing Time

Until 1979, everyone who wore contact lenses removed and cleaned them nightly. The introduction of "extended clothing" enabled wearers to sleep in their contacts. Now, two types of lenses are classified by wearing time:

• Daily wearable — must be removed nightly

• Extended wear — can be worn overnight, usually for seven days consecutively without removal

"Continuous clothing" is a term that's sometimes used to describe 30 consecutive nights of lens article of clothing — the maximum wearing time approved past the FDA for certain brands of extended vesture lenses.

When To Supplant Your Contact Lenses

Even with proper care, contact lenses (especially soft contacts) should be replaced frequently to prevent the build-up of lens deposits and contamination that increase the take a chance of eye infections.

Soft lenses have these full general classifications, based on how frequently they should be discarded:

Lens Replacement Frequency

• Daily disposable lenses — Discard afterwards a single day of article of clothing

• Disposable lenses — Discard every two weeks, or sooner

• Frequent replacement lenses — Discard monthly or quarterly

• Traditional (reusable) lenses — Discard every six months or longer

Gas permeable contact lenses are more resistant to lens deposits and don't demand to be discarded every bit often equally soft lenses. Often, GP lenses can last a year or longer before they need to be replaced.

The most frequently prescribed contact lens replacement schedule in the U.Southward. in 2017 was monthly (40 percent), followed by daily (35 percent), every 1 to ii weeks (24 percent) and annually (1 percent).

Contact Lens Designs

Soft contact lenses (both standard hydrogel and silicone hydrogel lenses) are available in a diverseness of designs, depending on their intended purpose:

Soft contact lens designs

• Spherical contact lenses take the aforementioned lens power throughout the entire optical part of the lens to correct myopia (nearsightedness) or hyperopia (farsightedness).

• Toric soft contact lenses have different powers in different meridians of the lens to correct astigmatism as well equally nearsightedness or farsightedness. [Read more nigh toric contact lenses.]

• Multifocal contact lenses (including bifocal contacts) contain different power zones for well-nigh and far vision to correct presbyopia also equally nearsightedness or farsightedness. Some multifocal lenses likewise can correct astigmatism. [Read more about bifocal contacts.]

• Cosmetic contact lenses include color contacts designed to change or intensify your eye colour. Halloween, theatrical and other special-effect contacts also are considered cosmetic lenses. A contact lens prescription is required for corrective contacts even if you have no refractive errors that need correction.

All of these lenses tin exist custom fabricated for difficult-to-fit eyes. Other lens designs besides are available — including lenses fabricated for employ in special situations, such as correcting for keratoconus.

More Contact Lens Features

Bifocal contacts for astigmatism. These are advanced soft contacts that correct both presbyopia and astigmatism, then you can remain spectacles-free subsequently age 40 even if you have astigmatism. [More nearly bifocal contact lenses for astigmatism.]

Contacts for dry eyes. Are your contacts uncomfortably dry? Certain soft contact lenses are specially made to reduce the risk of contact lens-related dry eye symptoms. [More about contact lenses for dry eyes.]

Colored lenses. Many of the types of lenses described above likewise come up in colors that tin enhance the natural color of your eyes — that is, make your light-green optics fifty-fifty greener, for example. Other colored lenses tin totally change the color of your eyes, as in from brown to blue.

Special-consequence lenses. Besides called theatrical, novelty, or costume lenses, special-effect contacts take coloration one step further to make you look like a cat, a vampire, or another alter-ego of your selection.

Prosthetic lenses. Colored contact lenses also can be used for more medically oriented purposes. Opaque soft lenses called prosthetic contacts can exist custom-designed for an middle that has been disfigured by injury or disease to mask the disfigurement and match the appearance of the other, unaffected eye.

Custom lenses. If conventional contact lenses don't seem to work for you, you might be a candidate for custom contact lenses that are made-to-gild for your private middle shape and visual needs.

UV-inhibiting lenses. Some soft contact lenses help protect your optics from the sunday's ultraviolet rays that can cause cataracts and other eye problems. Only because contacts don't cover your unabridged eye, yous still should wear UV-blocking sunglasses outdoors for the all-time protection from the sun.

Scleral lenses. Big-diameter gas permeable lenses chosen scleral contacts are peculiarly designed to care for keratoconus and other corneal irregularities, likewise as presbyopia.

Myopia control contacts. Special contact lenses are beingness developed to dull or stop the progression of nearsightedness in children. [More about myopia control.]

Which Contact Lens Is Correct for You?

First, your contacts must address the problem that is prompting you lot to wear lenses in the first place. Your contact lenses must provide good vision by correcting your myopia, hyperopia, astigmatism, or some combination of those vision issues.

Second, the lens must fit your eye. To do that, lenses come up in tens of thousands of combinations of diameter and curvature. Of grade, not every lens brand comes in every "size."

Your ECP is skilled in evaluating your middle's physiology, and your eyesight, to determine which lens best satisfies the ii criteria higher up.

Third, y'all may have some other medical need that drives the selection of lens. For example, your ECP might pick a detail lens if your eyes tend to be dry.

Finally, consider your "wish listing" of contact lens features — colors, for example, or overnight article of clothing.

When you lot and your ECP decide on the right lens for you, you'll exist given a contact lens prescription. Y'all'll be able to buy a supply of lenses from your ECP or from the many other outlets that sell contact lenses.

Contact Lens Wear and Care

Caring for your contact lenses — cleaning, disinfecting and storing them — is much easier than it used to be.

A few years ago, you would have needed several bottles of cleaning products, and perhaps enzyme tablets, for proper care. Today, well-nigh people can use "multipurpose" solutions — pregnant that one product both cleans and disinfects, and is used for storage.

People who are sensitive to the preservatives in multipurpose solutions might need preservative-free systems, such every bit those containing hydrogen peroxide. These do an splendid job of cleaning contacts, but information technology's very important to follow the directions for using them. The solution should not come up into contact with your eyes until soaking is complete and the solution is neutralized.

Of course, y'all can avoid lens care altogether past wearing daily dispensable contact lenses.

Contact Lens Problems

Trial and error oftentimes is involved in finding the perfect lens for you lot. People react differently to diverse lens materials and cleaning solutions.

Besides, the correct "parameters" of your lens — that is, power, diameter, and curvature — tin can be finalized but after yous've successfully worn the lens. This is especially true for more circuitous fits involving extra parameters, such every bit with bifocals or toric contact lenses for astigmatism.

If yous experience discomfort or poor vision when wearing contact lenses, chances are that an aligning or modify of lens can assist.

Today, more contact lens choices than e'er are available to provide condolement, good vision, and good for you eyes. If your eyes or lenses are uncomfortable or you are not seeing well, remove your lenses and visit your eye care professional person to explore bachelor remedies for contact lens discomfort.

Buying Contact Lenses

You lot tin can buy replacement contact lenses at many places, and some offering a better value than others. Discover out more about where to buy contacts and ownership contact lenses online.

More Information About Contacts

For more than information about contacts, visit our contact lens FAQ, heart doctor Q&A and contact lens news pages.

Notes and References

Contact Lenses 2017.Contact Lens Spectrum. January 2018.

Folio published in Feb 2019

Page updated in January 2022

cummingsbefornes.blogspot.com

Source: https://www.allaboutvision.com/contacts/contact_lenses.htm

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