Polycarbonate vs High-Index Lenses [What Is the difference?]

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Whenever you go to purchase your prescription glasses whether it be online at the local optical retailer you are often faced with the decision on what kind of lenses you should get. These lens options usually include plastic, glass, polycarbonate, trivex, and high-index.

Polycarbonate vs. High Index Lenses

A pair of black eyeglasses

Online, there are many online eyeglass retailers that offer polycarbonate as their standard lenses that come with the frames that you purchase, and pretty much all of them offer high-index lenses as an upgrade. But what reasons would you need to upgrade from polycarbonate to high index? Below you will find a breakdown of each material so next time you make your eyewear purchase you can make an informed decision between polycarbonate vs high-index lenses.

Index of Refraction

When we are talking about the index of lenses, we are referring to the lens material’s ability to bend light, this is referred to as the “index of refraction.”

This index of refraction is the ratio of the speed of light traveling through air, to the light traveling through the eyeglass lens material. Which means that lens materials that are more effective at bending light have a higher index than those lens materials that do not bend light as efficiently

Always remember that lenses with a higher index of refraction are thinner, lighter, and have less distortion (thicker lenses tend to have more distortion). Therefore if you have two lenses with the same power, the lens material that has a higher index of refraction will always be thinner.

Standard plastic lenses have an index of refraction of 1.50, and glass lenses have an index of refraction of 1.52.

Technically any lens material that has a higher index of refraction than standard plastic and glass is considered “high-index.”

RELATED: Best Anti-Fog For Your Prescription Lenses

Polycarbonate Lenses

Polycarbonate lenses have had a long history of usage in other industries such as for the cockpits in fighter planes, space shuttle windshields, and astronaut helmet visors.

In response to a demand for materials for eyeglass lenses that were lightweight and impact-resistant polycarbonate was introduced into the optical world in the 1980s.

Today polycarbonate is the standard lens material for many online eyeglass retailers, and they are standard in all children’s glasses, safety glasses, and sports goggles.

Polycarbonate lenses have an index of refraction of 1.59, and will generally be about 20% thinner than standard plastic lenses. Polycarbonate lenses also provide you with protection from 100% of the harmful UV rays from the sun.

I generally recommended people with prescriptions anywhere between +/-0.50 to +/-4.00 to go with polycarbonate lenses. These lenses provide you with a durable and impact-resistant lens that is perfect for anyone, but especially if you are an active individual. Take a look at the video below to hear an explanation of what polycarbonate lenses are by FramesDirect.

High-Index Lenses

High-index lenses generally are recommended to individuals who have stronger prescriptions, so that they have the thinnest, lightest, visually appealing, and most comfortable pair of eyeglasses that they can buy.

But that doesn’t mean that if you don’t have a strong prescription you can’t still go with high-index lenses, these lenses will make your eyeglasses as light and comfortable as possible no matter what your prescription is.

High-index lenses have an index of refraction that starts at around 1.61 and can go as high as 1.74. These lenses are perfect for anyone with stronger prescriptions, but not only limited to just those individuals. Even if you have a weaker prescription but you just want your glasses to be as light as possible, high-index lenses would work for you as well.

I generally recommended anyone with a prescription higher than +/-4.00 to go with a high-index lens to make their lenses are as thin as possible. This is especially true for anyone who is using a metal frame which exposes more of the lenses due to the thin frames. For anyone that has a prescription that is stronger than +/- 7.00 I definitely recommended going with the 1.74 high-index lens material which has the highest index of refraction to provide you with the thinnest possible lens.

Do You Have To Get Polycarbonate or High-Index Lenses?

Technically you do not HAVE to get polycarbonate or high-index lenses after all these materials haven’t always existed. BUT, you must keep in mind that whenever you have a strong prescription and you decide that you want to go with a lens that has a lower index of refraction such as plastic, you will be able to see, but your lenses are going to be thicker. Whenever you have thicker lenses, this creates more optical distortion in your lenses, which leads to unwanted eyestrain and becomes more bothersome the longer you wear those glasses.

The few exceptions to this are children, who need to use polycarbonate for the added impact-resistance since they are active and need the added safety. Speaking of safety, individuals who use safety glasses or sports goggles also need to be in polycarbonate lenses due to its impact-resistant properties.

Thinner and lighter-weight lenses also benefit individuals who have strong farsighted prescriptions, which are thicker in the center of the lens and can be quite heavy for strong prescriptions. Cosmetically for farsighted people, it would reduce the amount of the magnified large bug-eye look that comes with having a strong farsighted prescription.

Worth Mentioning | Anti-Reflective Coating

There is no lens material that lets 100% of light pass through it. There is some light that is always reflected back off of the lens surface, which could cause annoying distractions, and lens flares reduce your clarity at night time. High-index lenses could reflect much more light than standard plastic and glass lenses, which means if you want to be able to have the best optical clarity out of your high-index lenses you will need to add an anti-reflective coating to your lenses. Most retailers will have their high-index lenses already prepackaged with anti-reflective coating, but some you will have to purchase it separately.

A high-index lens with anti-reflective coating on it will let up to 99.5% of the light pass through to your eyes giving you the best optical clarity and vision out of your glasses. Having anti-reflective coating on your lenses not only drastically reduces the reflection of your lenses, but could provide you with better clarity and sharper vision for your nighttime driving.

RELATED: How to clean polycarbonate and high-index lenses?

Conclusion

At the end of the day, the lens you might end up going with might be dictated ultimately by what your budget is. There are many reputable online retailers that offer polycarbonate without anti-reflective coating so there should be no reason why you shouldn’t at least get polycarbonate. Retailers such as Warby Parker offers an upgrade from their polycarbonate to high-index for only an additional $30 for single vision, which is by far one of the most affordable high-index upgrades available out there.

If any of this still sounds confusing to you, and you have any questions feel free to drop a comment below, or you can use the contact form to send us a message and we will get back to you as soon as we can.

If you are a prescription contact lens wearer be sure to check out where the best places to buy contact lenses online.


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16 thoughts on “Polycarbonate vs High-Index Lenses [What Is the difference?]”

  1. Hello Huy. Thanks so much for sharing your opinions and thoughts about polycarbonate vs high-index lenses. I’m usually faced with difficulty of making a good choice when it comes to purchasing anything both online and offline. This article will guide me through on the right lenses I should for.

    I’d go for Polycarbonate Lenses due to its ability to protect the eyes from 100% of the harmful UV rays from the sun because I walk alot.

    Reply
    • Hi there Barry, polycarbonate is definitely a great choice. That was always my go to recommendation regardless of prescription, the added impact resistance is great added protection. With so many eye injuries happening all the time it is good to be extra protective about our only two eyes. Thanks for stopping by!

      Reply
  2. Thanks a lot for the great comparison on Polycarbonate vs High-Index Lenses.

    I got new insights from your helpful post. My wife and I use eyewear but to be honest we are not aware there are so much things we need to know. We just purchase it in the near by shop. Through your post I learned about Index of Refraction and high-index which is very helpful.

    Your recommendation based on the prescription is very helpful in our purchase decision.

    Thanks again for the informative post.

    Wishing you great success!

    Paul

    Reply
    • Hi there Paul, thanks for stopping by. I am glad you found the information helpful! There are many different options when it comes to eyewear. At times you may be limited to what the retailer of your choice carries, but there are many options when it comes to eyewear. 

      Reply
  3. I personally don’t wear eyeglasses although can imagine that lighter weight lenses would be much more preferable. As well as having a thinner lens especially with the more fragile and dainty frames. 

    If I did wear glasses I think it would be an automatic upgrade for me. 

    If ever I do end up needing glasses I will have a little more knowledge on the lenses. Thanks for the info.

    Christine 

    Reply
  4. Thanks so much for your knowledge! I have serious eye problems since baby (34 years ago haha) and I used bad contact lenses during kindergarten, heavy glass glasses that hurt my nose badly. Luckily I’ve been wearing some comfy contact lenses since I was 11 years old, but unfortunately allergic after so many many years. This article? It’s a miracle. With +8 both eyes, I finally found a solution for my relaxing daily moments and for whenever I can’t use my lenses any more. Thanks so very much! 🙂

    Reply
    • I am happy you found my information helpful! I can’t imagine how heavy glass lenses would be for that kind of prescription, luckily there are much lighter lens materials these days. Thank you so much for stopping by!

      Reply
  5. Hi my glasses have standard Anti-Reflective coating. Is the AR a spray on the lens or was the AR built n the lens? I am asking because I wanted to know if optician can add a premium AR on my glasses

    Reply
    • Hi there Pati! Thanks for stopping by! Anti-Reflective is a coating that is applied to the lens. Generally, you would only be able to have your lenses made with the premium AR from the beginning and it is not usually able to be applied after you have had your glasses. When AR coating is applied on a lens the surface has to be perfect, any little scratch even fine ones or dust will cause defects in the coating. Hope that answers your question.

      Reply
  6. Hi there, based on my newest prescription OD+1.25-0.75×95 OS+1.50-0.75X97 +1.00, would you recommended polycarbonate or high index 1.74 for my soon coming eyeglasses and would you recommended it for prescription sunglasses as well or keep the sunglasses with polycarbonate. I loved the Crizal which made things clearer at night and I just want to get things right the first time around. Any help or suggestions are greatly appreciated. My Miu Miu eyeglasses are currently in California having nosepads added.

    Reply
    • Hey there, You would be just fine in polycarbonate based on that prescription, but if you wanted a thinner and lighter lens then 1.67 high index is fine. No need to spend the extra money for 1.74 high index. Thanks for stopping by.

      Reply
  7. I just got new glasses and frames (titanium). I need lightweight as I seem to never stop noticing the weight of glasses on my face and ears. These glasses are light as a feather and comfortable. I have progressives and the receipt for these glasses lists this “PALHI-PAL Hi Index/Poly RX” What are my lenses made of??? I know that polycarbonate and high index are not the same thing. Does the slash mean hi index INSTEAD of polycarbonate? I know the PAL means progressive lenses. AR coating is also listed with a 2 year warantee. My previous glasses were progressive plastic. These new ones do not seem quite as crystal clear as my previous ones??

    Reply
    • Hi there, it appears that your prescription lenses are made out of polycarbonate. Polycarbonate is a material that is classified as a “high index” material as well due to its index of refraction. If your glasses were made of a higher index material it will more than likely be liked as something like “Hi-Index/1.67” or “Hi-Index/1.74”. If you got polycarbonate and you had a higher index material previously this could be the reason why everything doesn’t seem as crystal clear. 1.67 Hi-Index provides you with slightly better clarity. Hope that helps.

      Reply
  8. Hello, Huy Le ABOC

    Thank you very much for sharing your knowledge with the rest of us mortals. I was told that going with polycarbonate and not HI-index lenses can damage your eyesight eventually. Is this true? If it is, why do they still sell poly?

    Thank you very much for your response.

    Reply
    • Hello mortal, haha just kidding. That is absolutely not true, there is no reason why polycarbonate would be damaging to your eyes in any way. Polycarbonate does not provide you with the best clarity when compared to other materials but wouldn’t damage your eyes for any reason.

      Reply

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