by Dr. Melody Huang
Many patients are unaware that there are different contact lens materials available. The material can make a big difference to your vision, comfort and eye health. As a member of the ophthalmology team, knowing the pros and cons of different lens materials is essential to help patients understand why a particular contact lens is best for them.
History of contact lens materials
Some credit Leonardo da Vinci with the idea of the first contact lens. However, recent analysis shows that this may not be true.1. It was Sir John Herschel, a British astronomer, who came up with the first contact lens design in 1827. This design led to the creation of the first glass contact lens in 1887, which covered the entire eye.2!
In 1948, the first plastic contact lenses were introduced.2made of a material called polymethyl methacrylate (PMMA). These were hard contact lenses similar to the modern rigid gas permeable (RGP) contact lenses available today, except that they did not allow oxygen transmission. Few people still wear PMMA lenses because most doctors have switched from rigid lens wearers to RGP lenses because they are more breathable.
The first commercially available soft contact lens was introduced in 1971.2. These were made ofhydrogel, a hydrophilic (water-loving) polymer. The hydrogel plastic is soft and pliable when water is absorbed, but hardens when dry. In 1981, the concept of extended wear soft contacts was introduced. These contact lenses are designed to be worn overnight, not to be removed every night before bedtime. Then, in 1985, a hybrid lens appeared.3which are contact lenses that have a rigid center lens with a soft lens surrounding it.
Contact lenses became even more comfortable to wear when the first soft disposable contact lenses were released in 1987 and the first daily disposable contact lenses were released in 1995.2. Another significant milestone in the history of contact lenses is the introductionsilicone hydrogel(SiHy) who came to the United States in 20022. Highly breathable4The SiHy material has changed the way many eye care professionals prescribe contact lenses. This was followed by a range of silicone hydrogel products, including custom-made SiHy lenses and the first SiHy daily disposable contact lenses, which were launched in 2010.2.
soft contact lens materials
The soft contacts are mainly made of hydrogel or silicone hydrogel material. The properties of these materials can affect eye health and the overall patient experience of contact lenses.5.
Some important features include4:
Comfort (affects wettability, lens stiffness (or elastic modulus) and water content, among others)
Wear time (related to comfort and oxygen permeability issues)
Oxygen permeability (how much oxygen passes through the contact lens to reach the eye)
Handling (SiHy lenses may be easier to put on and take off)
Vision (impact on dryness and sediment)
The hydrogel material is extremely flexible due to its water content. This flexibility makes hydrogel contact lenses soft and comfortable for the wearer compared to rigid lenses.
The main hydrogel material used in soft contact lenses is poly(2-hydroxyethyl methacrylate), often called poly-HEMA. The oxygen permeability of hydrogel lenses depends on the water content. The higher the water content, the more oxygen can pass through the lens.
silicone hydrogel lenses
This new generation of lenses allows more oxygen to reach the eye than standard hydrogel lenses (approximately 5 times more oxygen6). Unlike hydrogel lenses, the oxygen permeability of SiHy lenses depends on the amount of silicone used, not the water content.5.
Silicone has a gel-like consistency that is flexible and is often used in other medical devices such as medical implants.7. Silicone is also used in modern RGP lenses to increase their oxygen permeability.
The first silicone hydrogel lenses were coated with a coating that improved their wettability.5. Wettability affects the comfort and dryness of contact lenses5. Some companies use plasma treatment while others use special wetting agents.8. These treatments increase the hydrophilic properties of the lens. In many cases, CooperVision incorporates the wettability of its silicone hydrogel lenses into the chemistry of the lens itself, so no surface treatment or internal wetting agents are needed.9. As this is the latest technology to achieve wettability in silicone hydrogel materials, they are called third generation materials.10.
What materials do eye care professionals recommend?
In 2019, practitioners in the US fitted patients with the following percentages of contact lens materials11:
65% silicone hydrogel
9% Rigid gas permeable
Worldwide, 72% of soft contact lens patients wear silicone hydrogel lenses. This includes data from different countries over the last 15 years.12.
From this data, SiHy lenses are the preferred material by contact lens fitting professionals.11!
Hydrogel vs. silicone hydrogel
Both types of soft lenses have advantages and disadvantages. However, as we saw in the previous section, most eye care professionals prescribe SiHy lenses for specific reasons.
One of the biggest advantages of silicone hydrogel lenses is that they minimize the risk of corneal damage.hypoxia13. This condition occurs when the cornea (the clear surface at the front of the eye) doesn't get enough oxygen.14. Hypoxia causes redness, blurred vision, abnormal growth of blood vessels in the cornea, and inflammation of the cornea.14. Hypoxia can also increase the risk of eye infections such as corneal ulcers.14.
Advantages of the hydrogel
very flexible material5
Good initial comfort5
Available in different modes (daily disposable, 2-week disposable, monthly replacement)sixteen
Available in different versions (spherical, toric, multifocal)sixteen
Disadvantages of the hydrogel
low oxygen permeability5
Potentially increased risk of eye infections and other hypoxic problems14
Not ideal for use at night.5
Advantages of silicone hydrogel
High oxygen permeability5(Video) 101: All You Need to Know About Contact Lenses
Easier to use (especially for new contact lens wearers)5
Extended wear and overnight wear (extended wear time) options available13
Available in different modes.sixteen
Available in various designs.sixteen
Disadvantages of silicone hydrogel
Early silicone hydrogel lenses sometimes had wetting problems, although newer SiHy materials have similar or better wettability than hydrogel lenses.
Early silicone hydrogel lenses used stiffer materials, however newer SiHy materials have better flexibility similar to hydrogels.9
Potentially increased risk of giant papillary conjunctivitis (GPC), an allergic reaction on the inside of the eyelid to early SiHy materials; however, this is not a problem with low-modulus daily monthly lenses and newer SiHy lenses.18
Slightly higher price for newer lenses like clariti®1-day lenses are close to price parity with 1-day hydrogel lenses.
silicone hydrogel contacts on the market
Silicone hydrogel lenses are available in all types and designs. Some popular brands include:
air optics®*^Aqua z Hydraglyde®
air optics®Day Night®
spicy®oasis®z Hydraclear®Also *^
My day® *
Daily Total 1®^
spicy®oasis®1 day with HydraLuxe™*
*Indicates availability of toric lenses, ^Indicates availability of multifocal lenses (including toric multifocals for some brands)
Contact lenses for overnight and long-term wear
Contact lenses approved for sleep use are usually made of silicone hydrogel.5.
When you are awake, your eyes receive oxygen through the tear film that is distributed over the eye every time you blink. When your eyes are closed, the palpebral conjunctiva (tissue lining the inside of the eyelid) carries oxygen and nutrients to the cornea.19.
Sleeping with contact lenses reduces the amount of oxygen your eyes receive. This increases the risk of corneal hypoxia and infection. People who sleep with contact lenses are also more prone to eye dryness, inflammation and allergies because they wear contact lenses for longer periods of time and clean them less often.14. Deposits and allergens are more likely to accumulate on contact lenses.
Ideally, patients should remove their contact lenses before going to bed. However, this is not practical in some cases where patients need to be ready at all times, such as first responders or military personnel.
If sleeping without contacts is not an option, contacts at night or for extended periods of time are the next best option. Because these lenses have high oxygen permeability, they are safer to wear while sleeping compared to standard hydrogel lenses.6.
Extended wear lenses are usually worn for up to 6 nights (7 days). After resting the eyes without contact lenses for one night, the extended wear program can be resumed the next night. The eye care professional should determine the appropriate wearing time and provide the patient with detailed instructions on the care, insertion and removal of lenses.
SiHy extended wear lenses include:
air optics®Water from Hydraglyde®
air optics®Day Night®
The materials make the difference
Choosing the right contact lens material can improve comfort and vision. This is especially true for patients with sensitive eyes, allergies, dry eyes, or other conditions that may affect contact lens wear.
Many studies show that the main reason patients stop wearing contact lenses (when patients stop wearing them) is discomfort20. It's important for contact lens patients to know that there are options. Some lens materials may work better for a person than others.
You can really amaze your patients by educating them about contact lenses. Let them know they don't have to stick with the same contact lenses they've been wearing for the last 10 years just because they're "fine."
So the next time a patient asks, "Is there really a difference between all these contacts?" you'll have an answer for him!
did you know? CooperVision®has the world's largest portfolio of silicone hydrogel lenses. Learn more about each of our brand families using the links below.
clariti® 1 day
CLICK HERE TO WATCH PART 2: CL PROJECTS
Caroline PJ, Norman CW. The history of contact lenses: The Da Vinci code has been deciphered. Spectrum of contact lenses. https://www.clspectrum.com/issues/2020/february-2020/history-of-contact-lenses.
Heiting G. When were contact lenses invented? All about vision. https://www.allaboutvision.com/contacts/faq/when-invented.htm.
sick L.A. Basics of hybrid lenses. American Optometric Association. https://www.aoa.org/Documents/optometric-staff/Articles/Hybrid%20Lens%20Basics%20Article.pdf.
Musgrave CSA, Fang F. Contact Lens Materials: A Materials Science Perspective.Materials (Basel). 2019;12(2):261.
Vinita Allee Henry, Steve Diamanti, and Julie Ott DeKinder (2020), "Selection of Soft Materials (Hydrogel and Silicone Hydrogel)" in Clinical Manual of Contact Lenses, 5Onwyd., wyd. Ed Bennett in Vinita Henry, Chiny: Wolters Kluwer, size. 288-3
Efron N, Morgan PB, Cameron ID et al. Oxygen permeability and water content of silicone hydrogel contact lens materials.I wish you knew. 2007;84(4):328-337.
Heiting G. Silicone Hydrogel Contact Lenses: A Comprehensive Guide. All about vision.https://www.allaboutvision.com/contacts/silicone-hydrogel.htm.
Schorner S. Some facts about SiHy lenses. Optometry review. https://www.reviewofoptometry.com/article/some-facts-about-sihy-lenses.
Eye contact lens. Jan 2013;39(1):100-108.
Tighe B. A decade of silicone hydrogels. Eyes and Contact Lenses, Volume 39, Number 1, January 2013
Nichols JJ, Starcher L. Contact Lenses 2019. Spectrum of Contact Lenses. https://www.clspectrum.com/issues/2020/january-2020/contact-lenses-2019.
Morgan PB, Woods CA, Tranoudis IG et al. International contact lens prescription in 2019. Spectrum of contact lenses. https://www.clspectrum.com/issues/2020/january-2020/international-contact-lens-precribing-in-2019.
Stapleton F, Stretton S, Papas E et al. Silicone hydrogel contact lenses and the surface of the eye.around surfers. 2006;4(1):24-43.
Liesegang, T.J. Physiological changes of the cornea after the use of contact lenses.CLOSE.2002;28(1):12-27.
For eye health and comfort, this type of daily disposable contact lenses is for you. Cooper's vision. https://coopervision.com/blog/ocular-health-and-comfort-type-daily-disposable-contact-you.
O.D. Specifications. www.ODspecs.com. http://www.odspecs.com/.
Eiden SB Is one contact lens solution suitable for all? Corneal correction and contact lenses. https://www.reviewofcontactlenses.com/article/does-one-contact-lens-solution-fit-all.(Video) Monthly Contacts VS Daily - Which is better?
Eyes and contact lenses. January 2014; 40(1):51-57.
Holden BA, Sweeney DF. Oxygen tension and temperature of the upper palpebral conjunctiva.Acta Ophthalmol (Copenhagen). 1985;63(1):100-103.
Pucker AD, Tichenor AA. Overview of cases of opting out of contact lenses.Clin Optom (Auckl). 2020;12:85-94.
Contact Lenses 101 Part 1: Contact Lens Materials? ›
Contact lens materials are typically based on polymer- or silicone-hydrogel, with additional manufacturing technologies employed to produce the final lens.What material are contact lenses made of? ›
Contact lens materials are typically based on polymer- or silicone-hydrogel, with additional manufacturing technologies employed to produce the final lens.What material is precision 1 contact lens? ›
Precision1 uses a new silicone hydrogel material, verofilcon A, and includes a permanently adhered 'microthin' (2 to 3 µm) layer of moisture. Alcon says this feature, which it calls SmartSurface, improves comfort and supports a stable tear film.What is the best material for contact lens? ›
Silicone hydrogel lenses offer an increased level of comfort and oxygen throughout the day when wearing lenses. For two weekly and monthly contact lenses, silicone hydrogel material helps to ensure that your lenses remain breathable throughout their entire wearing cycle.What is the material in Somofilcon? ›
SILICONE HYDROGEL 1 Day (somofilcon A) Soft (hydrophilic) Contact Lenses for Daily Wear Single Use are a hydrophilic co-polymer of silicone containing monomers and hydrophilic monomers which is cross-linked with tetraethyleneglycol dimethacrylate and di-functional methacryloxypropyl-terminated poly(dimethylsiloxane).What are Acuvue contacts made of? ›
These lenses are made of a silicone hydrogel material containing an internal wetting agent, visibility tint, and UV absorbing monomer and are tinted blue using Reactive Blue Dye #4 to make the lenses more visible for handling.Are all contacts made of the same material? ›
Contact lenses are produced in a variety of different materials in order to guarantee the comfort, breathability and lasting moisture of the lens.What is the safest material for contact lenses? ›
Silicone hydrogel's high oxygen permeability means contact lens wearers are less likely to suffer from corneal hypoxia or a lack of oxygen supply to the cornea. Another benefit of high oxygen permeability is that silicone hydrogel contact lenses are much more suitable for extended or continuous wear.What contact lenses are made of silicone? ›
Popular brands of silicone hydrogel contact lenses include Acuvue Oasys (Vistakon), Air Optix Aqua (Alcon), Biofinity (CooperVision) and PureVision2 (Bausch + Lomb).What material is Oasys contact lens? ›
This is an advanced type of lenses which are softer and more porous than regular hydrogel lenses, which allows more oxygen to the cornea. Soft Lenses are made of water-containing plastics called hydrogels. These are thin and can conform to the surface of the eye.
What are the 3 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. ...
- Rigid Gas Permeable (RGP) Contact Lenses. ...
- Extended Wear Contact Lenses. ...
- Disposable (Replacement Schedule) Contact Lenses.
Contact lenses may seem like they are the same - simple pieces of plastic that correct your vision. However, there are several differences that can play a key role in the fitting your unique eyes. Different brands make contact lenses that vary in everything from material to shape to recommended replacement schedule.What material are Bausch and Lomb contact lenses made of? ›
Silicone Hydrogel material: Allows a high amount of oxygen to reach your eyes. Hence, provides superior eye health.What material is Hubble contact lens? ›
Hubble contacts are made with a material called Methafilcon A by Shine Optical Co. Essentially, the lenses only come in one shape and size and the material they're made from is outdated. Very few contacts are still made with Methafilcon A and most optometrists won't recommend products made from the material.What is Biotrue lens material? ›
The Bausch + Lomb Biotrue® ONEday lens material, HyperGel® (nesofilcon A), is a hydrophilic copolymer of 2-hydroxyethyl methacrylate and N-vinylpyrrolidone, and is 78% water by weight when immersed in a sterile saline solution.What material is Biotrue contact lenses? ›
Biotrue ONEday is made from HyperGel™, an innovative, next generation of daily disposable material that has the best features of conventional hydrogels and silicone hydrogels.Are all contact lenses made of plastic? ›
Soft, hard, and hybrid contact lenses are all made using types of plastic, but maybe not the kind of plastic that comes to mind when you hear that word. Different types of contacts are made using various high-tech polymers that allow oxygen to flow through to reach the cornea—a necessity when it comes to eye health.What are astigmatism contacts made of? ›
Toric contact lenses are made from one of two materials: Hydrogel. Silicone hydrogel.
Permanent contact lenses are a type of implantable lenses called phakic intraocular lenses (PIOLs), and are made of clear, flexible plastic.Which is the stiffest contact lens material? ›
For example, the highest Dk material (lotrafilcon A) is the stiffest, and the lowest-Dk material (galyfilcon A) is the softest.
Are Warby Parker lenses glass or plastic? ›
Our frames come standard with impact-resistant polycarbonate lenses that block 100% of UVA and UVB rays.What is the difference between ionic and nonionic contact lenses? ›
“Ionic: lenses have a negatively charged surface, thus will attract positively charged proteins in the tear film. “Non-ionic” hydrogel lenses are coated in order to reduce the negative surface charge, thus, reducing the attraction of protein deposits.Is there a better alternative to contacts? ›
Laser Surgery as a Contact Lens Alternative
Laser surgery corrects some of the common problems of vision such as nearsightedness, farsightedness, astigmatism, and presbyopia.
Silicone hydrogel lenses are made from a soft, flexible property that increases oxygen permeability. In fact, this type of contact lens material allows up to 5 times more oxygen to permeate through the lens to the eye than standard soft lenses.What type of contact lens is the most comfortable? ›
Lenses made from newer silicone hydrogel materials tend to be more comfortable. They allow more oxygen to pass through to the cornea and take less time to adapt to, as well as being comfortable for longer. Switching to daily disposable or silicone hydrogel lenses could significantly reduce any discomfort.What the difference between silicone hydrogel and hydrogel contact lenses? ›
Hydrogel lenses generally have a higher water content and much lower oxygen permeability than silicone hydrogel lenses. Low oxygen transmissibility is a major contributor in contact lens‐related complications, such as corneal inflammation or neovascularization (Dillehay 2007).Which lens is better silicone or acrylic? ›
Acrylic lenses are much more hydrophilic than silicone lenses. The contact angle (a measure that reflects relative hydrophobicity of intraocular lens (IOL) material) for acrylic lenses is 73 degrees, whereas for silicone it is 103 degrees.What is the disadvantage of silicone contact lenses? ›
The drawback of silicone hydrogel lenses is their tendency for the lens to collect more debris and protein deposits from your tears.What material are monthly contact lenses? ›
During the day, having your eyes open brings in oxygen to your cornea. Monthly and other extended wear contact lenses are typically silicone hydrogel lenses that have higher gas permeability: they allow five or more times the oxygen through the lens compared to standard contact lenses.What is the most popular type of contact lenses? ›
Roughly 50% of the weight of a soft lens is due to the water it contains, making them extremely comfortable and super easy for you to wear. Soft lenses are hands down the most popular type of contact lens. Approximately 90 percent of contact lenses worn in the U.S. are soft lenses.
What is the most common type of contact lenses? ›
Soft contacts are the most common type of contact lenses and account for over 85% of contact lenses dispensed. Traditional soft contact lenses consist of soft plastic polymers and water. They allow oxygen to permeate through the lens material to the cornea.Are hard contact lenses still made? ›
Hard contact lenses are the second option of contact lenses available. These lenses have come a long way since the 1970s. Hard contact lenses today are rigid gas permeable lenses which allow for more flexibility and oxygen to pass through the lens to the cornea, while still maintaining their shape on the eye.Does it matter what brand of contacts you get? ›
Different brands of contact lenses are made from different materials, and just because another brand has a similar base curve and diameter does not mean it will fit the same. Wearing the exact brand that you have been prescribed will help prevent medical problems and allergic reactions to the different materials used.Which contacts are better daily or monthly? ›
People with dailies don't have to worry about cleaning the lenses because you just throw them away each night and put in a new pair each morning. However, a monthly lens may work better for people who find solace in a daily cleaning routine or those who don't want to keep a large stock of contacts on hand.Who Cannot wear contact lenses? ›
Although, not everyone can wear them comfortably. Eye conditions, such as dry eye disease or blepharitis, may make wearing contacts uncomfortable and risky. A severe refractive error, allergies, or contact lens intolerance can also make wearing contact lenses difficult.Are contact lenses glass or plastic? ›
While plastic has become the most popular choice of lens material in recent years, glass lenses are still preferred by some for the following reasons: Clarity. Glass lenses provide the clearest vision with the smallest amount of distortion. Scratch resistance.What contact lenses are made from Methafilcon A? ›
Hubble Contacts are made of methafilcon A, a soft contact lens material that was FDA approved in 1986 and hasn't changed since. So why do I groan whenever I hear about Hubble Contacts? There are several reasons.What material are Easyvision contact lenses? ›
Easyvision Opteyes (Same as Biofinity) lenses are made from Silicone Hydrogel, using a specific formulation developed by CooperVision. They have a water content of 48%, and a Aspherical lens design.What is the Hubble contacts controversy? ›
The complaint alleges the defendant violated the Contact Lens Rule by: 1) failing to properly verify consumers' prescriptions; 2) selling contacts after prescription verification requests were denied; 3) altering prescriptions by substituting its own Hubble brand when that wasn't what the consumer was prescribed; and 4 ...Is Trivex or polycarbonate better? ›
Because of its high Abbe value therefore, Trivex lenses can offer a better optical experience than polycarbonate lenses. This is especially the case for those with higher prescriptions, as the severity of the aberrations tend to increase with stronger prescriptions.
Is Biotrue contact lens a silicone hydrogel? ›
Are Biotrue contacts silicone hydrogel? Biotrue ONEday contacts are not made from silicone hydrogel, but from hydrogel. There are pros and cons with both materials but hydrogel lenses are known for their high water content and comfort.Is CR-39 better than Trivex? ›
Like most plastics, CR39 is tough and resists scratching, heat and most chemicals. It is the clearest lens material in common use on the Abbe scale at an average value of 58. Comparatively, Trivex is the next clearest to CR39 at 45, and polycarbonate is 32 (highest numbers are better).Which is better ReNu or Biotrue? ›
Both multi-purpose solutions are designed to keep your contact lenses effectively clean as Biotrue has a dual disinfection system, compared to ReNu which has a triple disinfection system. Biotrue contact lens solution are more advance in that they deliver an even longer contact lens wear of moisture and hydration.Which is better ReNu vs Opti free? ›
These results demonstrate that Opti-Free Express provides greater lens wearing comfort than ReNu MultiPlus, especially later in the day. An improvement in lens comfort should translate into greater patient satisfaction, decreased contact lens dropout and greater patient retention.Are contact lenses made from Lucite? ›
The correct answer is lucite. The conventional hard contact lenses were made of a hard plastic material called polymethyl methacrylate also known as Lucite.Can you be allergic to contact lenses? ›
Contacts are actually made from medical grade, hypoallergenic materials. So, in most cases, the contact materials do not cause the allergic reaction. Rather, the 'allergy' is caused by a buildup of contaminants. However, in rare cases, people can develop an allergy to the actual lenses.Are contact lenses made from PVC? ›
Contact lenses are made from Polyvinyl chloride. Polyvinyl chloride is provided as a great benefit as besides making lenses it is also helpful in making buildings, electronics health care's, and other sectors. The vinyl helps in producing sliding frames which are easily durable and helpful in making glasses.Can your body reject contact lenses? ›
There are many reasons that your eyes might reject your contacts. Your eyes can develop an intolerance to contact lens fluid, bacteria from unclean contacts, or even the material of the lenses themselves. Some common causes of contact lens intolerance include: Improper use, storage, or cleaning.What causes eye irritation when I put my contacts in? ›
Some of the reasons why you might experience contact lens discomfort include the wrong lens fit, poor hygiene practices, allergies, dry eyes, medications, and underlying conditions. A good aftercare routine can go a long way in helping you to reduce eye discomfort.What contacts are best for allergies? ›
ACUVUE® Theravision® with Ketotifen has built-in allergy medication, that is seamlessly embedded into the contact lens and offers triple-action relief. 50% of medication will release in the first 15 minutes of wear, and it will continuously deliver over the next 5 hours.
Is it safer to wear glasses than contact lenses? ›
Almost all complications are due to poor hygiene and maintenance, but the fact remains that contact lenses do carry more risk than eyeglasses. Oversights in lens care can cause irritation, conjunctivitis, dry eye syndrome, and other uncomfortable eye problems.Are contact lenses microplastics? ›
As they go through sewage systems, contact lenses break down into smaller particles and ultimately form microplastics. These microplastics pollute the oceans and are mistaken for food by marine animals.Are contact lenses made from Teflon? ›
The correct answer is Hydrogel. Contact lenses are normally made of Hydrogel.Do contact lenses contain plastic? ›
Contact lenses have been used for decades to correct vision. Their materials have evolved to enhance vision as clearly as possible while maintaining the eye health of the user, ultimately resulting in a plastic polymer, silicone hydrogel.