Vision Care

Silicone Hydrogel Contact Lenses

Silicone Hydrogel Contact Lenses -AC Lens   The Benefits of Silicone Hydrogel Contact Lenses

   Silicone Hydrogel Contact Lenses are the latest development in soft contact lens materials. They are healthier than conventional soft lenses because they allow up to 6 times more oxygen to pass through them and increased oxygen transmission results in  better overall eye health. Advantages of silicone hydrogel contact lenses over conventional soft lenses include:

  1. More resistance to protein deposits
  2. Less drying of the lenses
  3. Lower risk of eye infection
  4. Easier handling due to increased rigidity of material
  5. Lower incidence of complications with extended wear use (overnight wear).


  The convenience of 30 days continuous wear (PureVision and Focus Night & Day), as well as the lowered incidence of eye health complications are quickly making silicone hydrogel contact lenses the most popular lens of choice for both eye care practitioners as well as patients.

Increasing Demand

    Most eye doctors believe that within the next 5 years, more patients will be wearing silicone hydrogel contact lenses than any other lens material. The current brands of spherical silicone hydrogel contact lenses available, in order of highest oxygen transmissibility to lowest, are:

  • Air Optix Night & Day Aqua contacts are approved for 30 day continuous wear. They were also the first FDA approved silicone hydrogel soft contact lenses.
  • Acuvue Oasys is approved for 2 week daily wear use or 6 night extended wear and is designed to be more wettable than the others and is therefore beneficial for people who have dry eyes.
  • Bausch & Lomb’s PureVision which is approved for 30 days continuous wear
  • Johnson & Johnson’s Acuvue Advance Plus which is a 2 week disposable lens and has not yet been approved for extended wear.

Astigmatism Correcting

    For astigmatism correcting, a toric silicone hydrogel lenses on the market is:

  • Bausch & Lomb PureVision Toric is a silicone hydrogel toric lens approved for 30 days extended wear with that fresh lens feeling.

    Studies have indicated that some lens care cleaning systems are compatible with silicone hydrogel contact lenses, while others may cause adverse reactions due to toxicity. Optifree Express and ClearCare multipurpose solutions are FDA approved to be used with silicone hydrogels.

Warning to Take Heed!

    In some studies, Renu Multiplus has been shown to cause an adverse corneal reaction when used with some silicone hydrogel contact lenses (source; Contact Lens Spectrum, August 2005). Additionally, UltraCare and SoloCare are not recommended for use with silicone hydrogel contact lenses.

Who Benefits Most From silicone hydrogel contact lenses?

    Most people would benefit from wearing silicone hydrogel contact lenses as compared to conventional soft lenses due to the health advantages. However, these lenses are especially useful in the following types of patients:

  • People with high prescriptions
  • Those whose eyes show signs that they require more oxygen
  • Wearers who experience end of day discomfort, dryness, or redness with their conventional soft lenses
  • People who wear their lenses for more than 12 to 14 hours a day (including overnight wear)
  • Kids and teenagers who tend to routinely over wear their lenses.
  • Additionally, since the Focus Night & Day as well as the PureVision lenses are approved for 30 days of continuous wear, they can be considered as a useful alternative for people contemplating refractive surgery.

No Silicone Hydrogels For You!

    Silicone hydrogels may not be the lens of choice for all patients. These lenses are generally more expensive than non-silicone hydrogel contact lenses. A more price conscious consumer may not prefer this option. Also, in some wearers, the silicone material tends to attract more lipid deposits, which may cause blurred vision and discomfort.

    There are some cases where a patient is not able to adapt well to the more rigid silicone material. This may result in some minor defects to the corneal integrity. These complications are rare and generally the health advantages and increased comfort that most wearers experience far outweigh the incidences of adverse reactions in those who do not adapt well to the material.

    Focus Night & Day were the subject of a three-year study by Ciba Vision. The company reported that the performance of this silicone hydrogel (SiHy) contact lens indicated that wearers enjoyed improved corneal health and reduced frequency and symptoms of contact lens related eye health symptoms.

    In particular, the study of 317 patients showed that Focus Night & Day wearers had less problems with red-eye, reduced dryness (22%) and neo-vascularization (the development of new blood vessels in the cornea) was reduced by 13%.

    During the first 8 months of 2005, Silicone Hydrogel contact lenses represented 24% of all soft contact lens sales. That is more than double the figure for the same period of 2004.

    Bausch & Lomb (manufacturer of Purevision, Purevision Toric and Purevision Multifocal contact lenses) reported that 40% of new contact lens fits are now silicone hydrogel contact lenses. They claim that 94% of wearers of their sector leading Soflens 66 Toric contacts can be migrated to the Purevision Toric lens without a script change.


    In conclusion, Prescription parameter ranges are being expanded for each of these lenses. Most recently, plus powers for Oasys were made available. Acuvue Oasys was also recently given FDA approval for up to 7 days of continuous wear. 

[2006 AC Lens, Reproduction Prohibited without Express Permission]

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By BrieferBob

A free-lance writer, the author is an FAA Licensed Private Pilot. He received his first Bachelor of Arts Degree from Cal State University, Northridge. He was inducted into both the Golden Key International Honour Society and Phi Theta Kappa Honor Society while pursuing a Bachelor Degree in Aviation Science at Utah Valley University. He's a traveler and a consumer who enjoys fly fishing, cycling, sailing, snowboarding, and golf on any other day. His writing offers briefings, advisories, alerts, and checklists for online shoppers.

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