Single vision lenses allow you to see a set focal distance with the full lens maximizing the field of vision. They may be used as distance/driving glasses, intermediate range glasses for computers or reading music, or as reading glasses.
Lined bifocals allow for a fuller range of vision with set visibly defined sections dedicated to distance, intermediate and near focal points.
Progressive lenses have a smooth transition between parts with different focal lengths, correcting for vision at all distances without the disruption of a defined line.
We offer three tiers of Progressive Lenses at My Vision.
Good – Varilux Comfort
Better – Varilux Physio W3
Best – Varilux X Design
For more information on Varilux Lenses click here.
Occupational progressive lenses are designed specifically for prolonged visual tasks, like working inside an office, to help alleviate eyestrain and even reduce fatigue. Occupational lenses maximize your visual range and focus at arm's length distances, providing a clearer viewing zone up to 5 times larger than conventional eyeglass lenses. And they are available with an array of lens treatment to eliminate glare and reflections from office lights and computer screens.
In the early days of vision correction, all eyeglass lenses were made of glass. Although glass lenses offer exceptional optics, they are heavy and can break easily, potentially causing serious harm to the eye or even loss of an eye. For these reasons, glass lenses are no longer widely used for eyeglasses.
In 1947, the Armorlite Lens Company in California introduced the first lightweight plastic eyeglass lenses. The lenses were made of a plastic polymer called CR-39, an abbreviation for "Columbia Resin 39," because it was the 39th formulation of a thermal-cured plastic developed by PPG Industries in the early 1940s. Because of its light weight (about half the weight of glass), low cost and excellent optical qualities, CR-39 plastic remains a popular material for eyeglass lenses even today.
In the early 1970s, Gentex Corporation introduced the first polycarbonate lenses for safety glasses. Later that decade and in the 1980s, polycarbonate lenses became increasing popular and remain so today. Originally developed for helmet visors for the Air Force, for "bulletproof glass" for banks and other safety applications, polycarbonate is lighter and significantly more impact-resistant than CR-39 plastic, making it a preferred material for children's eyewear, safety glasses and sports eyewear.
A newer lightweight eyeglass lens material with similar impact-resistant properties as polycarbonate is called Trivex (PPG Industries), which was introduced for eyewear in 2001. A potential visual advantage of Trivex is its higher Abbe value (see below).
In the past 20 years, in response to the demand for thinner, lighter eyeglasses, a number of lens manufacturers have introduced high-index plastic lenses. These lenses are thinner and lighter than CR-39 plastic lenses because they have a higher index of refraction (see below) and may also have a lower specific gravity.
All lightweight eyeglass lens materials have surfaces that are significantly softer and more prone to scratches and abrasions than glass lenses. The softest eyeglass lens is also the one that is the most impact-resistant: polycarbonate. But all plastic and high-index plastic lenses require a factory-applied anti-scratch coating for adequate lens durability.
Most of today's modern anti-scratch coatings (also called scratch coats or hard coats) can make your eyeglass lenses nearly as scratch-resistant as glass. But if you're hard on your glasses or you're buying eyeglasses for your kids, ask about lenses that include a warranty against scratches for a specific period of time.
An anti-reflective (AR) coating makes all eyeglass lenses better. AR coatings eliminate reflections in lenses that reduce contrast and clarity, especially at night. They also make your lenses nearly invisible, so you can make better eye contact and you and others aren't distracted by reflections in your lenses. AR-coated lenses are also much less likely to have glare spots in photographs.
Anti-reflective coating is especially important if you choose high-index lenses, because the higher the refractive index of lens material, the lighter the lenses reflect. In fact, high-index lenses can reflect up to 50 percent more light than CR-39 lenses, causing significantly more glare, unless AR coating is applied.
At My Vision, we offer three tiers of Antireflective coatings as well as a blue light blocking antireflective coating to meet all of our patient's needs and budgets.
Good – Crizal Easy
Better – Crizal Avance
Best – Crizal Sapphire 360
Blue Blocking – Crizal Prevencia
For more information on Crizal Antireflective coatings click here.
Cumulative exposure to the sun's harmful ultraviolet (UV) radiation over a person's lifetime has been associated with age-related eye problems including cataracts and macular degeneration.
For this reason, people should protect their eyes from UV beginning in early childhood. Thankfully, polycarbonate and nearly all high-index plastic lenses have 100 percent UV protection built-in, due to absorptive characteristics of the lens material.
But if you choose CR-39 plastic lenses, be aware that these lenses need an added coating applied to provide equal UV protection afforded by other lens materials.