How to Choose the Best Lens for Your Glasses?
Our eyeglass frame is important for appearance and comfort purpose; however, your eyeglass lenses should not only be trendy, but they must be comfortable offering correct vision and safety for long-term use.
A common mistake most people make when buying eyeglasses is not spending enough time to enquire about the lens materials, design and lens modeling process.
Eyeglass Lens Materials – Features and Benefits
In earlier days, all eyeglass lenses were made of glass. Although they gave precision, glasses are brittle and heavy to carry. For these reasons, glass lenses are no longer widely used for lens manufacturing.
Thickness of lens depends on its size and frame style. For thinner lenses, choose smaller, round or oval frames.
Plastic Lenses: Lightweight plastic lenses, made of polymer called CR-39 were first introduced in 1947 by the Armorlite Lens Company in California. Because of its light weight, low-cost and outstanding optical qualities, CR-39 plastic is still a widely used material even today!
Polycarbonate Lenses: In early 1970s, Gentex Corporation introduced the first polycarbonate lenses for safety glasses. Polycarbonate is lighter and more impact-resistant than CR-39 plastic, ideal for use in children’s eyewear, safety glasses, and sports eyewear.
Trivex is a newer lightweight eyeglass lens material with similar impact-resistant properties as polycarbonate.
High-index Plastic Lenses: In response to the increasing demand for thinner, lighter eyeglasses, a number of optical manufacturing companies introduced high-index plastic lenses. These lenses are thinner and lighter and have a higher index of refraction.
The index of refraction relatively measures the efficiency of an optical material to refract (bend) light depending on how fast light travels through the material. A lens made of a material with a high refractive index will be thinner than a lens made of a material with a lower refractive index.
Aspheric Design
In addition to choosing a lens material that has a high index of refraction, you should choose an aspheric designed lens. In this lens modeling process, the lens curvature changes gradually from the center of the lens to its edge letting the manufacturers use flatter curves without degrading their optical qualities. Because aspheric lenses are flatter than spherical lens designs, you can have a better appearance and also improved clarity.
Minimum Center Thickness (or Edge Thickness)
The size and shape of your eyeglass frame will also affect the thickness of your lenses, especially if you have a strong prescription. If you choose a smaller, well-centered frame, you can use thinner and light weight lens. Generally, the thinnest lenses are aspheric lenses made of a high-index material.
Article is posted by Optics Sourcing. To compare your quotes from qualified optics manufacturing vendors visit http://optics-sourcing.com .













