Silicone Hydrogel Contacts

Editorial note: Silicone hydrogel materials deliver more oxygen to the cornea than conventional hydrogel lenses (Dk/t typically 100–175 vs. 20–30) but vary in water content, modulus, and surface treatment. The right silicone hydrogel for you depends on tear film characteristics and lens-eye fit, which are clinical determinations. Pricing varies by retailer, prescription strength, and insurance coverage. Always consult your eye care professional before purchasing or changing lenses.

The Material Behind Modern Lenses

Silicone hydrogel (SiHy) is the dominant material category in soft contact lenses today, accounting for roughly 70–88% of new soft contact lens fits in recent industry surveys depending on region. The material was a clinical breakthrough when the first FDA-approved SiHy lenses (Bausch + Lomb's PureVision and CIBA Vision's Focus Night & Day) reached the U.S. market between 1999 and 2001 because they solved the fundamental limitation of conventional poly-HEMA hydrogel lenses: low oxygen transmission to the cornea. Per the American Academy of Ophthalmology, the cornea is avascular — it has no blood vessels and draws atmospheric oxygen through the tear film. SiHy materials add an independent oxygen pathway through silicone-rich polymer channels, with Dk/t (oxygen transmissibility through a lens of clinical thickness) commonly 5–6× higher than the conventional hydrogels they replaced.

SiHy vs Traditional Hydrogel

SiHy advantages: 5–6× higher oxygen transmissibility, lower hypoxia-related complication risk, FDA-cleared options for extended wear.

Conventional hydrogel advantages: Higher water content (favored for some dry-eye patients and for high-water toric SKUs not yet matched in SiHy), softer feel, often lower cost. CooperVision's Extreme H2O is the most commonly discussed high-water hydrogel for patients with documented silicone intolerance.

The brand-to-SiHy-material map (verify against the current product page; manufacturers occasionally reformulate):

• J&J Vision (Acuvue): Acuvue Oasys family on senofilcon A; Acuvue Oasys MAX 1-Day on senofilcon C
• Alcon: AIR OPTIX Night & Day Aqua on lotrafilcon A; AIR OPTIX plus HydraGlyde / AIR OPTIX for Astigmatism on lotrafilcon B; Dailies Total1 on delefilcon A; TOTAL30 on lehfilcon A; Precision1 on verofilcon A
• CooperVision: Biofinity on comfilcon A; MyDay on stenfilcon A; clariti 1 day on somofilcon A; Avaira Vitality on fanfilcon A
• Bausch + Lomb: PureVision on balafilcon A (the first commercially available SiHy); Bausch + Lomb ULTRA on samfilcon A; INFUSE on kalifilcon A

These materials look similar on a spec sheet but differ in modulus, wettability strategy, and water content — differences that matter for fit and end-of-day comfort. The trade-offs that still favor conventional hydrogel for a minority of patients are covered later in this guide.

How Silicone Hydrogel Works: The Science Explained

The cornea is avascular — it draws oxygen from the atmosphere through the tear film during open-eye wear, and from the palpebral conjunctiva (inner eyelid surface) during sleep. Conventional hydrogel lenses transmit oxygen by dissolving it into lens water content and letting it diffuse to the corneal surface; this created a structural ceiling because hydrogels above ~70% water become fragile and dimensionally unstable. SiHy adds an independent silicone-rich pathway that is oxygen-permeable regardless of water content, so a SiHy lens can run moderate water (commonly 33–55%) yet deliver Dk/t 4–6× higher than the highest-water conventional hydrogels.

Dk vs Dk/t: the two numbers that get confused

Two oxygen numbers appear in lens marketing material and they are not the same. Dk is the intrinsic oxygen permeability of the polymer itself, reported in barrer units (cm³ O&sub2; × mm / [s × cm² × mmHg], × 10⁻¹⁰). Dk/t is oxygen transmissibility through a lens of a specified center thickness (Dk divided by thickness in centimeters). Dk/t is the clinically relevant number because it captures both material capability and how the lens is actually manufactured — a high-Dk material in a thick lens can deliver less oxygen to the cornea than a moderate-Dk material in a thin one. Manufacturers commonly cite Dk/t at a −3.00D center thickness; values at higher prescriptions are somewhat lower because of thicker lens centers. Compare two SiHy lenses at matched thickness when you can.

The Holden-Mertz oxygen thresholds

The clinical thresholds used to set acceptable oxygen delivery come from work by Brien Holden and George Mertz published in Investigative Ophthalmology & Visual Science in 1984, and have been re-validated through the British Contact Lens Association (BCLA) and successive contact-lens-research literature. The two anchor numbers most commonly cited:

• Dk/t 24 — minimum to avoid clinically significant corneal swelling during open-eye daily wear
• Dk/t 87 — minimum to avoid clinically significant overnight corneal swelling during closed-eye sleeping wear, when the closed lid already reduces ambient oxygen by roughly 60%

Modern SiHy materials sit comfortably above both thresholds (typical Dk/t 100–175 at −3.00D), which is why the FDA has cleared several SiHy lenses for up to 30 nights of continuous wear. Conventional hydrogels typically run Dk/t 20–40 — clearable for daily wear under Holden-Mertz but not for routine overnight wear, one reason extended-wear conventional hydrogels were largely withdrawn from the market once SiHy reached scale. Oxygen is necessary for corneal health but it isn't the only variable; microbial keratitis risk during overnight wear remains the load-bearing safety concern. Wearing schedule decisions are an eye care professional's call.

Silicone Hydrogel Lens Comparison by Brand

Generations of Silicone Hydrogel Technology

Silicone hydrogel lens chemistry has moved through three generally recognized generations, each addressing limitations of the previous. The boundaries are approximate — manufacturers ship across generation lines simultaneously, and material codes can persist for years past the formulation refresh that introduced them — but the framework is useful for understanding why two SiHy lenses launched a decade apart can feel quite different on the eye.

First generation (1999–2004): Bausch + Lomb's PureVision (balafilcon A, 1999) and CIBA Vision's Focus Night & Day (lotrafilcon A, 2001) reached high oxygen permeability through stiff, high-modulus materials with intrinsically hydrophobic surfaces. To make the lens surfaces wettable, manufacturers applied plasma surface treatment — a separate manufacturing step that creates a thin hydrophilic outer layer. These first-generation lenses delivered the oxygen-transmission breakthrough but could feel dry and deposit-prone for some wearers, and the plasma layer's durability over a 30-day wear cycle was a known consideration.

Second generation (2004–2010): Acuvue Advance (galyfilcon A, 2004) and Acuvue Oasys (senofilcon A, 2005) from Vistakon, plus AIR OPTIX (lotrafilcon B, 2006) from CIBA Vision, used lower-modulus materials with built-in wetting strategies. J&J introduced internal wetting agents — PVP (polyvinyl pyrrolidone) embedded in the matrix and continuously migrating to the surface during wear, branded HYDRACLEAR and later HYDRACLEAR PLUS. Alcon refined the surface-treatment approach with SmartShield. The result was lenses that felt closer to conventional hydrogel comfort while retaining the SiHy oxygen-delivery advantage; biweekly Acuvue Oasys remains a widely-fit lens two decades after launch.

Third generation (2010–present): CooperVision's Biofinity (comfilcon A) and MyDay (stenfilcon A, 2014) use naturally wettable SiHy polymers that require no surface treatment. Alcon's Dailies Total1 (delefilcon A, 2012) introduced water-gradient technology — lens core at roughly 33% water for oxygen delivery, surface at approximately 80% water mimicking the tear-film side of the cornea; TOTAL30 (lehfilcon A, 2021) brings water-gradient to a monthly schedule. Alcon's Precision1 (verofilcon A, 2019) uses SmartSurface technology, a thin permanent moisture layer at the lens surface. Bausch + Lomb's INFUSE (kalifilcon A, 2021) pairs SiHy chemistry with ProBalance technology designed to support tear-film stability. These third-generation advances have largely closed the comfort gap with high-water conventional hydrogels, particularly for digital-display-heavy wearers running 8–12-hour days.

The Hydrophobic Challenge: How Manufacturers Make Silicone Wettable

The central engineering challenge of SiHy is that silicone repels water. A lens surface that repels water would be uncomfortable and cause blurry vision because the tear film would not spread evenly. Four wettability strategies dominate the current market, and understanding which strategy a given lens uses helps explain the comfort differences between brands:

• Surface treatment (Alcon, Bausch + Lomb): Plasma oxidation modifies the outer surface to create a permanently hydrophilic layer. Alcon's SmartShield technology creates a thin hydrophilic shield that also resists deposit buildup.
• Internal wetting agent (Johnson & Johnson): PVP (polyvinyl pyrrolidone) is embedded throughout the lens matrix and continuously migrates to the surface during wear. This is the HYDRACLEAR and HydraLuxe family.
• Inherently wettable polymer (CooperVision): The polymer chemistry itself attracts water at the surface without separate modification. Biofinity's Aquaform technology arranges silicone and hydrophilic molecules into a balanced material.
• Water gradient (Alcon): Dailies Total1 and TOTAL30 use a silicone-rich core (~33% water) for oxygen delivery surrounded by a water-rich surface (~80% water) that mimics the tear-film side of the cornea.

SiHy vs. Traditional Hydrogel: When Hydrogel Wins

Despite SiHy's dominance, conventional hydrogel lenses remain the better fit for certain patients. A minority of SiHy wearers experience issues including contact lens papillary conjunctivitis (CLPC) — an allergic response triggered by deposits on the silicone surface — surface drying from silicone's hydrophobic properties, or solution incompatibility with specific SiHy materials. For these patients, high-water conventional hydrogel options like Extreme H2O (hioxifilcon, up to 59% water), Bausch + Lomb Biotrue ONEday (nesofilcon A, 78% water), or CooperVision Proclear (omafilcon B, 62% water with PC technology) may provide better day-long comfort.

Conventional hydrogel also remains the primary material for most colored contact lenses, including FreshLook ColorBlends and Acuvue Define, though AIR OPTIX Colors is a notable SiHy colored-lens exception. The American Optometric Association emphasizes that material selection should be individualized — the best lens is the one that provides optimal comfort, vision, and health for each specific patient, which is not always the highest-Dk option.

Extended Wear and Overnight Use

Silicone hydrogel's high oxygen permeability enabled the return of extended wear (overnight) contact lenses. Several silicone hydrogel lenses are FDA-approved for continuous wear: Air Optix Night & Day (up to 30 nights), PureVision (up to 30 nights), and Acuvue Oasys (up to 6 nights). The FDA approved these based on the high Dk/t values that provide sufficient oxygen during sleep, when the closed eyelid already reduces available oxygen by approximately 60%.

However, extended wear remains controversial in eye care. Even with silicone hydrogel, sleeping in contact lenses increases the risk of microbial keratitis by 5-10 times compared to daily removal. The cornea accumulates more inflammatory metabolites during sleep, and the closed-eye environment promotes bacterial growth beneath the lens. Most eye care professionals reserve extended wear for specific patient populations — those with dexterity limitations who cannot easily handle lenses, patients requiring 24-hour vision correction (emergency workers, military), or occasional overnight situations. For routine wearers, nightly removal and proper lens care remain the safest approach.

Choosing the Right Silicone Hydrogel Lens for Your Lifestyle

SiHy options span dozens of SKUs across four major manufacturers; the right pick depends on lifestyle and visual demands. Heavy digital-device users often do well on third-generation moisture-management designs — TOTAL30, Bausch + Lomb ULTRA, and Acuvue Oasys MAX are commonly discussed for late-day comfort under extended screen wear. Active and outdoor wearers may benefit from lenses with UV protection (most Acuvue SKUs include Class 1 or Class 2 UV blocking; manufacturers note these are not a substitute for UV-protective sunglasses). Allergy-prone wearers often do better on daily disposables — a fresh lens each morning means zero accumulated allergen load by end-of-day. Budget-conscious wearers can reach SiHy technology through value options like clariti 1 day (somofilcon A) or PureVision 2 at price points overlapping with conventional hydrogel monthlies. These are decision contexts your eye care professional can weigh against your tear film, corneal topography, and refractive needs during a contact lens fitting.

Editorial Team field notes

Three observations from the WholesaleContactCity Editorial Team's May 2026 research pass on the silicone-hydrogel category — cross-retailer SiHy daily-disposable pricing, when SiHy versus conventional hydrogel comes up in real fitting conversations, and the material-code-to-brand decoder that helps patients read their own lens box.

Cross-retailer May 2026 SiHy daily-disposable pricing. In our May 2026 cross-retailer survey across 1-800 Contacts, Lens.com, ContactsDirect, Walmart Contacts, and Costco Contacts, top SiHy daily-disposable SKUs landed in these per-90-pack ranges: Acuvue Oasys 1-Day HydraLuxe (senofilcon A) $68–$88, Dailies Total1 (delefilcon A) $78–$95, Precision1 (verofilcon A) $52–$72, MyDay (stenfilcon A) $58–$78, Bausch + Lomb INFUSE (kalifilcon A) $60–$80, clariti 1 day (somofilcon A) $40–$60. Costco and Walmart held the low end where stocked; 1-800 Contacts the high end. Annual-supply rebates ($50–$200 from MyAcuvue, MyAlcon, MyCooperVision, and B+L programs) further compress effective cost. Vision-plan in-network pricing (VSP, EyeMed, Davis Vision) and FSA/HSA eligibility per IRS Publication 502 can shift out-of-pocket cost more than the cross-retailer spread itself. See our 2026 contact lens buyers guide for a side-by-side comparison.

SiHy vs conventional hydrogel: when the conversation actually comes up. The default for new soft fits in May 2026 reader correspondence is silicone hydrogel for the oxygen-transmission reasons covered above. The conversation shifts toward conventional hydrogel in a defined set of situations: documented silicone intolerance from a prior fitting, recurrent contact lens papillary conjunctivitis (CLPC) attributed to deposits on a SiHy surface, sensitivity to the lower water content of typical SiHy materials, or a need for a high-water-content toric SKU that does not exist in current SiHy lineups. CooperVision's Extreme H2O (hioxifilcon, up to 59% water) is the most commonly discussed high-water-content hydrogel in this clinical conversation; Bausch + Lomb's Biotrue ONEday (nesofilcon A, 78% water) and CooperVision's Proclear (omafilcon B, 62% water with PC technology) come up alongside it. The trade-off is real — conventional hydrogels deliver less oxygen (Dk/t typically 20–40 vs 100–175 for SiHy) but can win on tear-film compatibility for the patients above. This is an eye care professional's call, not a checkout-screen substitution.

Material code to brand decoder: what the box actually says. The USAN-assigned material code printed on each lens box is the reliable way to verify what's in the package. Two code pairs commonly get confused at the patient level: lotrafilcon A vs B (A-suffix is the higher-Dk AIR OPTIX Night & Day Aqua; B-suffix is AIR OPTIX plus HydraGlyde / for Astigmatism) and senofilcon A vs C (A is the Acuvue Oasys family across daily and biweekly; C is the newer Acuvue Oasys MAX 1-Day). The brand-to-material map in the SiHy vs Traditional Hydrogel section above covers the rest of the lineup. Per AAO patient guidance, brand substitution at the retailer or pharmacy level is not appropriate for contact lenses the way it is for generic medications — the prescribed material reflects fitting characteristics specific to your eye, so a switch should go through your eye care professional as a refit, not a checkout-screen swap.

Disclaimer: Educational content only — not medical advice. Material codes, water content, and surface-treatment names cited from manufacturer product literature current at time of writing; manufacturers occasionally reformulate SKUs while retaining brand names. Verify against the current product page or your eye care professional before purchasing.

Frequently Asked Questions

Q: What is silicone hydrogel and why does it matter?

A: Silicone hydrogel is a contact lens material that combines silicone-rich polymer channels with a hydrogel matrix, transmitting roughly 5–6× more oxygen to the cornea than conventional hydrogel materials. About 70–88% of new soft lens fits in recent industry surveys use SiHy.

Q: Is silicone hydrogel better than regular hydrogel?

A: For most wearers, yes — SiHy delivers markedly higher oxygen transmissibility (Dk/t typically 100–175 vs 20–40 for conventional hydrogel). A minority do better on high-water hydrogel like Extreme H2O. Material selection is a clinical determination your eye care professional can make.

Q: What are the best silicone hydrogel contact lenses?

A: Commonly fit options include Acuvue Oasys (daily and biweekly, senofilcon A/C), Dailies Total1 (delefilcon A), Precision1 (verofilcon A), MyDay (stenfilcon A), Biofinity (comfilcon A, monthly), AIR OPTIX plus HydraGlyde (lotrafilcon B, monthly), and Bausch + Lomb INFUSE (kalifilcon A). See our daily lens guide.

Q: Can you sleep in silicone hydrogel contacts?

A: Some SiHy lenses are FDA-cleared for extended wear — PureVision and AIR OPTIX Night & Day Aqua (up to 30 nights), Acuvue Oasys (up to 6 nights). Even with cleared lenses, overnight wear raises microbial keratitis risk; nightly removal is the safer default per overnight wear guide.

Q: Why are silicone hydrogel lenses more expensive?

A: SiHy lenses require additional manufacturing steps — plasma surface treatment, internal wetting agents, or specialty polymer chemistry — to make the inherently hydrophobic silicone wettable. Value options like clariti 1 day (somofilcon A) and PureVision 2 have brought SiHy pricing closer to conventional hydrogel monthlies.

Q: Do silicone hydrogel lenses cause dry eyes?

A: Most wearers experience less end-of-day dryness on SiHy than on conventional hydrogel because SiHy materials dehydrate less. A subset experiences surface dryness from silicone's hydrophobic nature; third-generation moisture-management designs (water-gradient, internal wetting agent) and switching to a different SiHy material are the usual paths your eye care professional may discuss. See our dry-eye lens guide.

Q: What is Dk/t and why does it matter?

A: Dk/t is oxygen transmissibility through a lens of a specified center thickness — the clinically relevant number for cornea-reaching oxygen. The Holden-Mertz thresholds (1984) set Dk/t 24 as the open-eye minimum and Dk/t 87 as the overnight minimum. SiHy lenses commonly run Dk/t 100–175 at −3.00D, comfortably above both.

Q: Are all modern contact lenses silicone hydrogel?

A: No, though SiHy is the dominant default. Conventional hydrogel still serves patients with documented silicone intolerance, certain colored-lens lineups, and a few specialty SKUs. Rigid gas permeable (RGP) and scleral lenses use entirely different materials and serve clinical needs soft lenses cannot.

Last reviewed and updated: May 9, 2026