Which is better glass vs. plastic sunglass lenses?

If you’re in the market for a new pair of sunglasses, you’ve probably realized that there are plenty of lens options available — namely, glass and plastic. But do glass or plastic lenses make more sense for sunglasses?

Glass lenses are a classic choice and provide optimum clarity. But they can be really heavy, and if you’ve got a prescription, they get even heavier. Not to mention glass lenses are not the safest choice for eyewear, especially for kids. 

Plastic lenses tend to be the more popular option, especially when it comes to plano (non-prescription) sunglass lenses, but there are variations in quality which should be a consideration. 

Before you make a sunglasses decision, take a look at the benefits and limitations of both glass and plastic lenses. When it’s time to select a new pair of shades, it will be much easier to make the right choice.

SEE RELATED: Your guide to prescription sunglasses

Sunglass lens replacement: Glass lenses

Once upon a time, glass lenses were the only option for eyeglasses, including sunglasses. But a lot has changed, and according to The Vision Council, less than 6 percent of glasses sold today are made of glass.

Glass lenses may not be as common as they once were, but they still offer exceptional optics, plus they are more durable and less prone to distortion. With clearer, longer-lasting clarity than other lens materials, glass lenses are a great choice for those who rely on their sunglasses all day or must perform detailed work outdoors. 

Because glass lenses are prone to crack and shatter, they are typically not a good option for children, teens or sports activities. On the other hand, glass lenses are great for adults with stronger prescriptions, as glass lenses have become much thinner and are therefore the better option. 

Although glass-lens sunglasses remain one of the highest quality options on the market, they’re also heavier than plastic lenses and can limit your selection of frames. For example, glass lenses would not be an option for semi-rimless or rimless sunglasses. 

WEIGHING YOUR SUNGLASSES OPTIONS? Shop for sunglasses at an optical store near you or an online eyewear retailer. 

Sunglass lens replacement: Plastic lenses

The first plastic eyeglass lenses were introduced by Armorlite Lens Company in California in 1947. While there have been numerous advances in eyeglasses since then, CR-39 plastic is still known for its excellent optical quality, durability and low cost.

A primary benefit of plastic lenses is how easily they allow for lens treatments like tinting and UV protection. Plastic lenses also can be coated to protect against scratches, but keep in mind, neither glass nor scratch-resistant plastic lenses are 100% scratch-proof. 

Plastic lenses also lead the way in terms of safety and durability. These lenses pose a lower risk of injury, making them better suited for children, teens and active adults.

Plastic is also cheaper and lighter weight than glass, which is why the vast majority of non-prescription sunglasses and clip-on sunglass lenses are made of this inexpensive-yet-durable material. 

The best lenses for sunglasses

Both glass and plastic lenses have their benefits, but which is best for your next pair of sunglasses? 

Many sunglasses are available in both glass and plastic lens options, but the most important factor is to ensure your lenses effectively block UV rays. 

According to the American Optometric Association, sunglasses should meet the following criteria to keep your eyes protected:

• Lenses should block 99% to 100% of both UVA and UVB radiation. 

• Lenses should screen out 75% to 90% of visible light. 

• Sunglasses should be well matched in color and absorption and free of distortion and imperfection.

Glass vs. plastic lenses: a quick comparison

Here is a brief comparison of glass vs. plastic lenses to help you decide which option is best for you:

• WEIGHT: Plastic is about half the weight of glass, so plastic lenses are a more comfortable choice for long-term wear.

• COST: Glass lenses are generally less expensive than comparable plastics.

• OPTICAL CLARITY: Glass has more optical clarity than plastic and offers little to no distortion. 

• UV PROTECTION: Regular plastic eyeglass lenses block most UV light, but adding a UV-blocking dye boosts UV protection to 100 percent for added safety.

• LONGEVITY: Due to its construction, glass is more durable than optical plastic. 

• IMPACT RESISTANCE: Glass is prone to shattering and splintering, making plastic a safer choice, especially for children’s eyewear. 

• AVAILABILIY: Glass and plastic lenses are both readily available, but plastic lenses will fit more frame options. 

• VERSATILITY: Plastic lenses are offered in a wider variety of colors and designs than glass lenses. Plastic also tends to be a better choice for sunglasses due to the coating and color options. 

The sunglasses lenses that are best for you

Glass lenses tend to be limiting in terms of frame options and tinting capabilities. Your need for prescription vs. non-prescription sunglasses will also likely affect your decision. 

If you’re in the market for new prescription sunglasses, or replacement sunglass lenses, your best bet is to get a recommendation from your eye doctor on glass vs. plastic sunglass lenses. 

QUESTIONS ABOUT PRESCRIPTION SUNGLASSES? Schedule an appointment with an eye doctor near you.

Page published on Sunday, March 29, 2020