Acuvue is a registered trade name for a brand of the first disposable contact lenses that became available on the market in the 1980s. Although they are disposable daily lenses, they can be worn up to 7 days. Acuvue 2 is an upgraded product that can be worn up to 2 weeks. Acuvue 2 also differs slightly from the original lens in terms of ingredients and features.
Etafilcon A
Like the original Acuvue lens, Acuvue 2 lenses are made of a substance known as etafilcon A. In an article published in Investigative Ophthalmology and Visual Science in 2002, the authors describe etafilcon A as a cross-linked copolymer of 2-hydroxyethyl methacrylate that is composed of an ionic compound, a concentration of 2 percent methacrylic acid and 58 percent water. In fact, in a patient instruction guide furnished by the manufacturer, Vistakon, etafilcon A is simply referred to as a hydrophilic material, which means that it has the ability to absorb water and helps the contacts to remain flexible and soft while being worn.
The manufacturer says that it took several years to develop this technology and that the manufacturing process involves multiple patents. In addition, Vistakon claims that performance and comfort are consistent with each disposable lens because the unique manufacturing process ensures that each one produced is identical to the next.
In the February 2006 issue of Contact Lens Spectrum, Eric Papas, Ph.D. and Mark Willcox, Ph.D. provided a comparative analysis of contact lens materials in promoting eye health based on a review of previous studies. The scientists found that patients wearing contact lenses made from etafilcon A experienced more redness after 30 days of continuous use than those using lenses made from lotrafilcon A or balafilcon A. This suggests that etafilcon A may have lower oxygen permeability than some other fluoroether-based silicone hydrogels, which is why lengthy extended wear is not recommended.
UV Blocker
Acuvue 2 contact lenses contain a built-in ultra-violet radiation blocker in the form of a UV-absorbing monomer. However, while this helps to minimize harmful UV radiation to the cornea, the lenses do not protect the entire eye or darken as photosensitive eyeglass lenses do. The manufacturer recommends wearing UV-absorbing eyewear when appropriate.
Cosmetic Tint
According to Acuvue-Now.com, Acuvue 2 contact lenses are available in 10 different tinted shades. The Acuvue 2 Colours Opaques include pearl grey, deep blue, sapphire blue, jade green, hazel green, warm honey and chestnut brown. Acuvue 2 Enhancers are available in emerald green, aquamarine and ocean blue.
References
- Investigative Ophthalmology and Visual Science; Influence of Wear and Overwear on Surface Properties of Etafilcon A Contact Lenses and Adhesion of Pseudomonas aeruginosa; Gerda M. Bruinsma et al.; 2002;43:3646-3653
- Acuvue: Patient Instruction Guide for VISTAKON (etafilcon A) Contact Lenses
- Contact Lens Spectrum; Reducing the Consequences of Hypoxia: The Ocular Redness Response; Eric Papas, Mark Willcox; February 2006
- Acuvue-Now.com: Acuvue 2 Colours
