How to choose the best lenses for your glasses

More than your frames, your lenses will determine how happy you will be with your eyeglasses.

Buying eyeglass lenses is not an easy task. In fact, there are so many choices for lenses and coatings, it's easy to be confused about what's worth buying.

Why choosing the right eyeglass lenses is so important

When buying eyeglasses, the frame you choose is important to your appearance, but the eyeglass lenses you choose influences four factors: appearance, comfort, vision and safety.

A common mistake people often make when buying eyeglasses is not spending enough time considering their choices of eyeglass lens materials, designs and coatings.

Eyeglasses: Tips to Help You Pick the Right Lenses

Glass lenses.

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.
Plastic lenses.

In 1947, the first lightweight plastic eyeglass lenses were introduced. The lenses were made of a plastic polymer called CR-39. 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.
Polycarbonate lenses

In the early 1970s, the first polycarbonate lenses were introduced for safety glasses. Later that decade and in the 1980s, polycarbonate lenses became increasingly popular and remain so today. Originally developed for helmet visors for the United States 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. In 2001, a newer lightweight eyeglass lens material known as Trivex was introduced with similar impact-resistant properties as polycarbonate.
High-index plastic lenses

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.

Eyeglass Lens Coatings

There are almost as many coatings as there are lenses.

Anti-reflective.

Tinted lenses

Mirror coatings

Scratch-resistant and ultraviolet protection

What Are Polycarbonate Lenses?

Polycarbonate lenses are distinguished by their resilient, shatterproof, and built-in scratch-resistant properties. Impact resistance sets them apart from other eyeglass lenses. This makes them an optimal choice for people with active lifestyles who are more prone to dropping or scratching their eyeglasses. Polycarbonate lenses are also ideal for children’s eyewear and prescription safety glasses.

Polycarbonate Lenses Advantages & Disadvantages

All eyeglass wearers should weigh both the pros and cons of polycarbonate lenses before making any purchasing decisions. Your eye doctor can also provide more information on any specific questions you may have.

Durable, providing extra safety to your eyes and promoting better eye health
10 times more resistant to impact than plastic eyeglasses, so they don’t shatter or break as easily
Boast scratch resistance so they last longer than regular plastic lenses
The refractive index of polycarbonate lenses is 1.59, which means that they tend to be 20 to 25 percent thinner than plastic eyeglasses
Generally weigh about 30 percent less than plastic eyeglasses
Don’t add thickness to correct vision
Minimize distortion
Completely block the sun’s UV rays
Are ideal for anyone prone to impact
Come in all types — from strong prescriptions to glasses for specific eye concerns

Do polycarbonate lenses provide UV protection?: Eye safety is important, but it goes beyond your prescription. Polycarbonate lenses also protect from harmful UV rays. The lenses have a natural blocker to prevent ultraviolet radiation from damaging your eyes. The UV protection, coupled with their durability, makes polycarbonate lenses ideal for people who tend to be active outdoors.
How are polycarbonate lenses different from glass or plastic lenses?: Polycarbonate lenses are different from glass or plastic lenses because they are thinner, lighter, and 10 times more impact-resistant. They provide extra safety for your eyes without sacrificing comfort or fit. Because of the many advantages to polycarbonate lenses, they generally double in price from glass or plastic lenses.
What are polycarbonate lenses made of?: Polycarbonate lenses are made of a thin, lightweight plastic that is known for its impact resistance and UV protection.

Trivex Eyeglass Lenses: Tough and Lightweight

Trivex lenses, developed in the United States by PPG Industries, are available in a wide variety of lens designs and features, including progressive lenses and photochromic lenses.

For the best comfort, vision and appearance, it's a good idea to have anti-reflective coating applied to Trivex lenses. This microscopic coating eliminates light reflecting from the front and back surfaces of the lenses, giving the lenses a crystal-clear appearance.

How Trivex Differs from Polycarbonate

Trivex and polycarbonate lenses have a lot in common when it comes to being exceptionally lightweight and impact-resistant — properties that make both lenses equally suited for safety glasses, sports glasses and other protective eyewear.

Lens materials with a high Abbe value tend to cause less chromatic aberration than those with low Abbe values. Trivex lenses have an Abbe value of 45 (better than average among eyeglass lens materials); polycarbonate lenses have an Abbe value of 30 (lowest among all lens materials).

Who should wear lenses made with Trivex material?

Lenses made with Trivex material are a great choice for anyone who leads an active life and expects clear, crisp vision, lightweight comfort and the ultimate in protection from their eyewear.

Consider the patient’s prescription…

Trivex material provides precise optical performance for every prescription. The majority of your patients—approximately 85%—fall within the prescription range of +3.00 D to -3.00 D and will gain the most from the benefits of Trivex material in an attractive and comfortably thin lens. For patients with more severe prescriptions or sensitivity to chromatic aberration, smaller frame styles minimize any appearance of lens thickness.

A perfect fit for children’s lenses…

With Trivex material, children gain the benefits of impact resistance PLUS great optical performance. Lenses made with Trivex material pass some of the optical industry’s highest standards for impact resistance.* Even better, you can provide that protection without compromising visual performance for reading and schoolwork.

Compatible with all lifestyles and frame styles...

For the fashion-conscious, lenses that provide optical quality, lightweight comfort, strength and protection are always in style! Trivex material is a perfect fit for all frame designs, and it is especially well-suited for rimless (drill-mount) and semi-rimless (supra) styles. The robustness of Trivex material is unmatched by any other lens material, delivering durability, ultra-lightweight comfort, and precise optics in an attractively thin lens that can satisfy your patients’ individual styles.

High index: A type of thinner, lighter lenses for glasses

High-index eyeglass lenses are the right choice if you want thinner, lighter lenses and eyeglasses that are as attractive and comfortable as possible. Thinner, lighter high-index lenses are especially recommended if you have a strong eyeglass prescription for nearsightedness, farsightedness or astigmatism. But high-index lenses can make your eyeglasses noticeably slimmer, lighter and more attractive regardless of how strong your prescription is.

Most eyeglass wearers are nearsighted, which requires corrective lenses that are thin in the center but thicker at the edge of the lens. The stronger the eyeglass prescription, the thicker the edges.

Advantages of high-index lenses

Thinner. Because of their ability to bend light more efficiently, high-index lenses for nearsightedness have thinner edges than lenses with the same prescription power that are made of conventional plastic material.

Lighter. Thinner edges require less lens material, which reduces the overall weight of the lenses. Lenses made of high-index plastic are lighter than the same lenses made in conventional plastic, so they're more comfortable to wear.

High-index glass lenses also have thinner edges, but high-index glass is heavier than conventional glass, so there is not as much weight savings with glass as there is with plastic lenses.

What Are Photochromic Lenses?

Photochromic Lenses look like regular clear lenses when indoors but automatically darken when moving into a brighter area. Ultraviolet (UV) rays from the sun affect the molecules in the photochromic lenses so they change colour. They will darken in the light even on overcast days as UV rays still penetrate clouds.

This provides you with the best possible vision in all lighting through different shades of tint, without you even needing to think about it. As Transitions is the most well-known brand of photochromic lenses, these types of glasses are often referred to as ‘transition lenses’. They’re also sometimes called adaptive lenses, auto-tinted lenses or variable-tint lenses. Photochromic glasses are not to be confused with polarised glasses (sunglasses). These have a set tint that protects from glare but they aren’t changeable; they don’t adapt to light in the same way photochromic lenses do.

Benefits Of Photochromic Lenses?

They help reduce eye strain, eye damage and potential heightened risk of cataracts later in life by blocking up to 100% of UVA/UVB light.
Convenience - there’s no need to carry both glasses and sunglasses, swapping between the two
It may save you money - although photochromic glasses can be more expensive than ordinary prescription glasses, they’re effectively two-in-one, meaning you won’t have to buy separate glasses and sunglasses