Glass Lenses Vs. Polycarbonate Lenses

Glass lenses have been around for about 1,000 years. Polycarbonate lenses, also known as the “plastic” lenses, were developed in 1953. What are the benefits and drawbacks of each lens? Is one type of lens significantly better than the other? Some people have a strong loyalty to one side, so in this article glass lenses and polycarbonate lenses will battle it out in five rounds.

Clarity

What does camera lenses, microscopes, and binoculars all have in common? They are made out of glass. This is because these tools require precision clarity which means that glass lenses are the most optically clear.

This doesn’t mean polycarbonate lenses are unclear. It is actually important to note that most people can not even tell the difference in the clarity between glass and polycarbonate lenses nowadays. Polycarbonate lenses have come a long way since their creation and are actually considered the standard lenses in the sunglasses industry.

The winner in this round: Glass

Scratch Resistant

Scratches on lenses can ruin your favorite sunglasses. Although you can always buy replacement lenses, you want to make sure the lenses you do have last you for a long time. So in this round who offers better scratch resistance?

Glasses lenses have the upper hand in this round. It is really hard to scratch them, although not impossible. For this reason, glass lenses don’t really require any additional scratch-resistant coating. Polycarbonate lenses alone are more prone to scratches. This is why it has an additional layer to help with scratch resistant and improve durability. It is important to note that if you follow our guide to caring for your sunglasses you will decrease your chances of scratches, regardless if you have a glass or polycarbonate lenses.

The winner in this round: Glass

 

Impact Protection

People who wear their sunglasses while being active and parents who are shopping for their smaller children may be concerned with the impact protection of certain sunglasses. Impact protection means that the lens will not shatter if it takes a hit. This includes dropping your sunglasses on the ground or flying projectiles hitting your sunglasses.

Both safety and sports eyewear use polycarbonate for their lenses. This is because polycarbonate lenses have the best impact protection overall. Glass lenses will shatter when it undergoes a hard impact, which can be very dangerous if it shatters while you are wearing them.

Weight

The weight of sunglasses is important to consider if you are a person who tends to be sensitive to these type of things or if you are planning to use your sunglasses for hours on end.

Glass is a heavier material than plastic, therefore, glass sunglasses can become uncomfortable to wear for long periods of time. If someone is sensitive to pressure or wants to wear their sunglasses for a prolonged period of time, polycarbonate lenses are recommended.

The winner of this round: Polycarbonate

UV Protection

Ultraviolet protection in sunglasses was something that was talked about in detail in the article, “Do Sunglasses Need UV Protection?”. To recap, it is important you use sunglasses with 100 percent UV protection since damage from UV rays is cumulative over a person’s lifetime.

Polycarbonate inherently blocks 100 percent of UV rays, without requiring additional coatings. Glass, on the other hand, requires a special coating in order to block any UV rays. If you are purchasing glass lenses, make sure they have this additional coating to protect your eyes from the UV rays. 

The winner of this round: Polycarbonate

Glass Lenses Summary

Glass lenses are optically clear, clearer than polycarbonate lenses. It is also scratch resistant and does not require any additional scratch-resistant coating. A positive thing about glass lenses that were not previously mentioned in the article, is that for prescription lenses, glass is recommended for bifocal or trifocal lenses due to its ability to be molded together without a noticeable edge. However, glass lenses do not have impact resistance. So if you drop it or a flying projectile hits your glasses, there is a strong possibility that it will shatter and that can be very dangerous. Glass lenses are heavier than polycarbonate, so if you plan on wearing your sunglasses for long periods of time, be mindful of this fact since it might start to become uncomfortable. Another factor is that glass lenses do not automatically have UV protection. You have to make sure the pair of glass lenses you buy have that additional coating to protect your eyes from UV rays.

Polycarbonate Lenses Summary

Polycarbonate lenses are not as clear as glass lenses, but the difference is not really significant to most people. These lenses are not scratch resistant like glass, so it does need an additional scratch-resistant layer. The impact protection on polycarbonate is so good that both safety and sports eyewear use polycarbonate for their lenses. Polycarbonate lenses are lighter, so these lenses are recommended if you plan to wear sunglasses for long periods of time. Polycarbonate inherently blocks 100 percent of UV rays which protect your eyes. Polycarbonate is easier to treat with virtually all tints. This allows them to be available in a wider variety of colors than glass lenses.

Summary

The overall winner based on these five rounds is polycarbonate lenses. Glass lenses won clarity and scratch resistant. Polycarbonate lenses win the categories of impact protection, weight, and UV protection. This comparison is very two-dimensional though. We make the assumption that each category has the same weight which is not true. Some people might value some qualities more than others. Examine the facts and consider your own personal day-to-day activities. Here at Fuse, we believe the benefits of polycarbonate outweigh the drawbacks and therefore we only sell polycarbonate lenses. I suggest you try them out for yourself to draw your own conclusions.