Thursday, September 13, 2007

Selecting Lenses Materials for Your New Reading Glasses.

Several materials of Reading Glasses lenses. Glass, Plastic, polycarbonate , Trivex and high-index materials. you can compare all materials before buy new Reading Glasses.

Glass
Glass lenses are becoming outdated. Glass is the material that has the truest optical properties and is least likely to scratch. Glass lenses are heavier and thicker than plastic lenses. Though glass lenses offer no safety protection. Price more expensive than plastic cause glass lenses difficult to manufacture.The only benefit to glass lenses is their superior scratch resistance.

CR-39 Plastic
CR-39 Plastic lenses is the standard plastic in the optical shops today. it lighter and thinner more than glass lenses, and is very cost-effective. These lenses are suitable for most prescriptions and can be coated to provide scratch resistance, ultra-violet protection and anti-glare qualities. CR-39 lenses are also available in fashion tints, sunglasses, or treated to darken outdoors. CR-39 lenses are not suitable for safety purposes, children, or people with severely compromised vision.

Polycarbonate
Polycarbonate lenses are a popular choice for a variety of needs.Polycarbonate lenses thinner and lighter than CR-39 30% and benefit of impact-resistance, scratch-resistance,ultra-violet protection . All safety lenses certified by OSHA for use in the workplace are made of polycarbonate. These lenses are recommended for athletes, children and those with severely compromised vision to protect their eyes from injury.because of their thinner and lighter qualities, are a good choice for children, sports, safety, and people with moderate to high prescriptions. Anyone with more than three diopters (+3.00 or -3.00 written on the prescription) of visual correction will notice the improvement in comfort over glass or CR-39 lenses. Polycarbonate lenses can be tinted for comfort, made into polarized sunglasses, treated to darken outdoors or to reduce glare.

Polycarbonate lenses are not the thinnest lenses available, and they can cause visual distortion at the edges in high prescriptions or those lenses including astigmatism. Even with these drawbacks, these are the best lenses for safety glasses, children, or those who want more protection for their eyes in case of an accident. Many insurance companies and optical retailers discount polycarbonate lenses for children’s spectacles.

Trivex
trivex lenses is a relatively new material, trivex lenses are the lightest choice available and come with built-in ultra-violet protection. They are also the best lenses for prescription sunglasses, as they accept the tinting process with the sharpest visual results. Trivex lenses are impact-resistant, but they are not yet certified for safety eyewear. They are the most versatile lightweight choice for all prescriptions and lifestyles and are suitable for any lens coatings or treatments—especially tinting.

Trivex lenses are sometimes marketed as Phoenix, Eagle Vision or Trilogy lens materials. This is the best lens for people who desire lightweight eyewear. They are also the best lens choice for rimless and drill-mounted eyewear styles as they will not chip or crack at the drilled points. An added benefit of trivex lenses is that fact that the lens, in single vision prescriptions, is virtually distortion-free, eliminating the need to turn your head to see through the clearest portion of the lens.

Hi-index

High-index lenses are the most expensive, and usually must be special ordered. They are not suited for children or athletes. Hi-index is recommended for those who are tired of thick, unattractive spectacle lenses and don’t mind the added cost.

The least expensive lens choice is CR-39 plastic. All of the thinner and lighter materials are manufactured using advanced technology and will be more expensive.

The most widely available and least expensive thin, light lens is polycarbonate. This material is stocked in most one-hour shops, boasts excellent scratch-resistance, and has a proven track record of great performance.

If your current spectacle lenses magnify or distort the appearance of your eyes, try lightweight lenses in your next pair. These lenses almost always improve the appearance of your eyewear and minimize the negative effects of a strong prescription.

Lightweight lenses will also improve the comfort of your eyewear. Heavy lenses can cause red indentations on the bridge of the noise or painful pinching behind the ear, often leading to headaches.

Reading Glasses should be comfortable, attractive and suited to your individual needs. With the many lens choices widely available now, every prescription can be customized to suit the wearer’s needs perfectly.

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