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Soft contact lenses are one of several types of contact lenses for corrective vision eyewear as prescribed by optometrists and ophthalmologists.

Background

It has been suggested that this section be split out and merged into the article titled Contact lens#Soft lenses, which already exists. (Discuss) (January 2022)

In the US market, soft contact lenses are approved by the US Food and Drug Administration. The American Optometric Association published a contact lens comparison chart called Advantages and Disadvantages of Various Types of Contact Lenses on the differences between them. These include:

• soft contact lenses
• rigid gas-permeable (RGP)
• daily wear
• extended wear
• disposable
• planned replacement contact lenses.

The US Food and Drug Administration (FDA) defines soft contact lenses as:

made of soft, flexible plastics that allow oxygen to pass through to the cornea. Soft contact lenses may be easier to adjust to and are more comfortable than rigid gas permeable lenses. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eye while you wear your lenses.

History

The first contact lenses were made of glass, in 1888. Initially the glass was blown but soon lenses were made by being ground to shape. For the first fifty years, glass was the only material used. The lenses were thin, yet reports of injury were rare. In 1938 perspex (polymethylmethacrylate, or PMMA) began to replace glass in contact lens manufacture. PMMA lenses were easier to produce so the production of glass lenses soon ended. Lenses made of PMMA are called hard lenses. Soft contact lenses were first produced in 1961 by Czech chemical engineer Otto Wichterle using polyhydroxyethylmethacrylate (pHEMA), a material that achieved long-term commercial application. Lenses made of polyacrylamide were introduced in 1971.

Types

The FDA classifies soft contact lenses into four groups for the US market. They are also subcategorized into 1st generation, 2nd generation, and 3rd generation lens materials. These 'water-loving' soft contact lens materials are categorized as "Conventional Hydrophilic Material Groups ("-filcon"):

Note: Being ionic in pH = 6.0 - 8.0".

The FDA has been considering updating soft contact lens group types and related guidance literature.

Contact lens polymers

The materials that are classified in the 5 FDA groups include the ones listed in the next 5 sections:

Hydrogel groups

Below is a list of most contact lens materials on the market, their water percentage, their oxygen permeability rating, and manufacturer brands. Note that the higher the oxygen transmissibility rating, the more oxygen gets to the eye.

Low water nonionic

High water nonionic

Low Water ionic

High Water ionic

Silicone hydrogel polymers

Production generations

There are three generations of silicone hydrogel contact lens materials:

References

1. "About Contact Lenses - clma.net". clma.net. Contact Lens Manufacturers Association. Retrieved 18 June 2016.
2. Denise Hampton, Ph.D (13 May 2014). "Contact Lens Safety - Ophthalmic Devices Panel" (PDF). www.fda.gov. FDA Division of Ophthalmic and Ear, Nose and Throat Devices. p. 97. Archived from the original (Microsoft PowerPoint) on 18 June 2016.
3. "Caring for Your Vision: Advantages and Disadvantages of Various Types of Contact Lenses". www.aoa.org. American Optometric Association. Retrieved 18 June 2016.
4. Center for Devices and Radiological Health. "Contact Lenses - Types of Contact Lenses". www.fda.gov. U.S. Food and Drug Administration. Retrieved 18 June 2016. This article incorporates text from this source, which is in the public domain.
5. ^ "Polymers in everyday things – Contact Lenses" (PDF). rsc.org. Royal Society of Chemistry. Archived from the original (PDF) on 19 June 2016. Retrieved 19 June 2016.
6. "The FDA has created the 4 Lens groups of hydrogels Materials to clarify categories of similar polymers for investigating solutions approvals". Archived from the original on 2016-08-10. Retrieved 2016-06-28.
7. Ophthalmic Devices Panel of the Medical Devices Advisory Committee (May 13, 2014). "FDA Executive Summary Prepared for the May 13, 2014 Meeting of the Ophthalmic Devices Panel of the Medical Devices Advisory Committee" (PDF). U.S. Food and Drug Administration. p. 2. Archived from the original (PDF) on 7 August 2015. Retrieved 18 June 2016.
8. Loretta B. Szczotka-Flynn (February 2005). "Contact Lens Materials: Advocating a New Lens Group". Contact Lens Spectrum. Archived from the original on 6 October 2015. Retrieved 18 June 2016.
9. "Contact Lens Compendium". contactlensupdate.com. Contact Lens Spectrum. Retrieved 18 June 2016.
10. Tina Kiang; Joseph Hutter; J Angelo Green; K Scott Phillips; Malvina B Eydelman (10 Nov 2011). "Updating the Contact Lens Classification System" (PDF). Food and Drug Administration. Archived from the original (PDF) on 17 November 2011.
11. "Contact Lenses: Manufacturing/Chemistry" (PDF). www.fda.gov. U.S. Food and Drug Administration. n.d. p. 25. Archived from the original (PDF) on 1 May 2015. Retrieved 18 June 2016.
12. "Editorial - Should Silicone Hydrogels be Placed in a Separate FDA Soft Contact Lens Category?". www.siliconehydrogels.org. Retrieved 18 June 2016.
13. Stretton, Serina (October 2004). "Should Silicone Hydrogels be Placed in a Separate FDA Soft Contact Lens Category?". siliconehydrogels.org. Retrieved 3 September 2020.
14. "Contact Lens Spectrum - Soft Contact Lenses". www.clspectrum.com. Contact Lens Spectrum. Retrieved 19 Feb 2019.
15. "CooperVision Product Reference Guide - 2019" (PDF). coopervision.com. CooperVision. Retrieved 19 Feb 2019.
16. "Acuvue Tech Specs - Winter 2017" (PDF). www.acuvue.com. Johnson & Johnson. Retrieved 19 Feb 2019.
17. "Contact Lenses: Bausch + Lomb". www.bausch.com. Bausch & Lomb. Retrieved 19 Feb 2019.
18. "Scout by Warby Parker (90 Pack) Contacts". Warby Parker.
19. "Miru 1 Day Contacts". LensPricer.
20. "10.2.4 AONDA Product Page | MyAlcon".
21. Dr. Karen French (12 May 2008). "The Performance of Galyfilcon A" (PDF). OpticianOnline.Net. Contact Lens Monthly. Retrieved 18 June 2016.
22. "Dailies TOTAL1® Lens Parameters and Fitting Guide | Alcon".
23. David L. Kading (May 2014). "New Lens Technology Targets Improved Vision and Comfort". Contact Lens Spectrum. Vol. 29.
24. Lens Parameters pi.bausch.com Retrieved 30 March 2023
25. "Bausch + Lomb INFUSE - Optix-now". Optix-now - Your Vision Care Guide. Retrieved 2020-12-23.
26. "Miru 1month | Menicon America". Menicon America. Retrieved 2021-05-01.
27. "TOTAL30® Parameters and Contact Lens Technology | Alcon".
28. https://www.accessdata.fda.gov/cdrh_docs/pdf18/K180322.pdf
29. https://www.accessdata.fda.gov/cdrh_docs/pdf18/K183670.pdf
30. "Precision7 Contact Lenses | Lenspricer".
31. "Looking at Silicone Hydrogels Across Generations". www.optometricmanagement.com. Optometric Management. Retrieved 18 June 2016.
32. Carnt, Nicole (May 2008). "3rd Generation Silicone Hydrogel Lenses". www.siliconehydrogels.org. Retrieved 5 October 2021.

• Contact lenses
• Eye care in the United States
• Medical equipment
• Medical technology
• Medical devices
• Czech inventions