High Index lenses are thinner, stronger, and more versatile than standard eyewear lenses. They are made from extremely durable plastic and are regarded as the best lenses you can get for your prescription glasses. Their key benefits include lighter weights and much thinner lens construction which improves fit and clarity.
What Are High index lenses?
High index lenses work by bending light more efficiently than their conventional counterparts. Referred to as the index of refraction, this is a ratio used to determine the speed at which light passes through a given lens material. Because high index lenses can transmit and bend light more efficiently than standard lenses, they can be made considerably thinner and lighter.
Thinner lenses are especially a considerable benefit for those that are nearsighted (most people), meaning they have lenses that are thinner in the center and get thicker at the edges. With high index lenses, these people can now more easily fit their stronger lenses in the same stylish frames as those with much weaker prescriptions.
High-index lenses are available in a vast range of indices, all of which can be found in the range of 1.53 to 1.74. Lens index is determined by a measurement of light refraction and lenses with a refraction index of 1.70, or higher are up to 50% thinner than standard plastic lenses.
Determining which lens is right for you can be a bit confusing but note that the higher the index number, the thinner and lighter the lenses are. Of course, we always recommend consulting with your eye doctor before selecting a new lens to make sure you are choosing the best lens for your specific needs.
Lens Index Chart: A Visual Comparison
Polycarbonate vs Trivex vs 1.60 vs 1.70 vs 1.74 Lenses
There is a lot of “good” to be gained from high index lenses, and if you have a strong prescription, you won’t want to miss out on their many benefits.
Thinner, Lighter, & Stronger
High index lenses come in a variety of indices ranging from 1.53 to 1.74, with “true” high index starting at an index of at least 1.60. At this index level, you will begin to benefit from a significantly thinner lens, as we mentioned briefly above.
In fact, high index lenses of 1.60 or higher typically result in a 25% – 50% reduction in overall lens weight compared to conventional lenses. As a result of the thinner lens, you will benefit from a significantly lighter lens as well.
High index lenses are also known for their superior strength and are second only to polycarbonate in durability and impact resistance.
Again, for those of you that have had strong prescription resulting in thick lenses, this is a real game changer as you will literally be lifting the weight of your glasses off of your face.
More Clarity & Less Distortion
Other benefits include increased clarity and less lens distortion when compared to standard lenses. High index lenses refract light more efficiently than lower index lenses resulting in a much thinner lens overall.
They are also available in an aspheric design which is especially helpful if you are nearsighted. Aspheric lenses are made flatter than conventional lenses allowing for much better clarity with far less distortion. The aspheric design also helps to reduce the “bug eye” look for anyone with a very strong prescription.
Greater Frame Selection
With standard lenses, people with stronger prescriptions may not be able to choose from many frames due to the lens edge being too thick to fit or seat properly. High index lenses create that significantly thinner edge we discussed above which means you can fit your lenses in just about any frame you like.
Disadvantages of High Index Lenses
There is very little to dislike about high index lenses, but there are two key drawbacks that can’t be ignored.
Increased Cost
The most obvious drawback of high index lenses is their cost. Lens cost varies significantly depending on the retailer, but expect to pay anywhere from $25 – $200 more for your index lenses online.
The vast price range is determined partly by the eyewear retailer or brand you choose but can be blamed mostly on the exponentially increasing costs of higher index lenses. Simply put, the larger the index number, the thinner the lens, and the more you can expect to pay.
Additionally, you can expect to spend even more than most online retailers should you decide to go to a brick and mortar optician.
Last, you may also want to avoid high index lenses for your first pair of glasses altogether. Your prescription could frequently change in the early stages resulting in multiple costly lens changes. In some instances, the retailer or your local optician may have a buyer satisfaction policy that protects you from lens changes for a period of days, usually 30 – 60 days.
Increased Lens Reflection
Another critical drawback of high index lenses is their inherent ability to reflect light, as much as 50% more than standard lenses. Thankfully, this is a mostly insignificant issue that can be all but eradicated by the addition of a quality anti-reflective (AR) coating to the lens.
A quality anti-reflective coating will eliminate 99% of reflections making the lenses nearly invisible (good for photographs). The AR coating is also a significant benefit at night as headlight reflections are significantly reduced increasing clarity and sharpness while driving.
Different Types of High Index Lenses
1.74 High Index Lenses
1.74 high index lenses achieve the designation as the thinnest lenses available for sale in the United States under current regulations. They are easily considered the ultimate in lightweight lens technology and provide unparalleled clarity and sharpness along with incredible durability.
1.74 high index lenses can get up to 10% lighter & thinner than 1.67 high index lenses and a whopping 50% lighter & thinner standard CR-39 lenses of the same prescription.
Key Benefits
Up to 10% lighter & thinner than 1.67 high index lenses.
Up to 50% lighter & thinner standard CR-39 lenses of the same prescription.
Flat, aspheric design for minimal lens distortion.
The ultimate in optical clarity and sharpness.
Best For
Anyone that desires the absolute best in thin, lightweight lens technology. They are recommended for prescriptions with a sphere (SPH) of +/- 9.25 and above, along with a cylinder (CYL) of +/- 4.25 to +/- 6.00.
Costs
$85 – $200 more than standard depending on the retailer, brand, & prescription.
1.67 High Index Lenses
1.67 high index lenses will be the first real dramatic jump into high index lenses for most people. Additionally, this is the most common index of lens used for those with moderate to stronger prescriptions.
They are remarkably thin lenses and remain an excellent choice for anyone seeking comfort paired with sharp, minimally distorted vision. They are up to 20% thinner & lighter than polycarbonate and 40% thinner & lighter than standard CR-39 lenses with the same prescription.
Key Benefits
Up to 20% Lighter & thinner than Polycarbonate lenses.
Up to 40% lighter & thinner than standard CR-39 lenses.
Mostly flat aspheric design for lower lens distortion.
Outstanding optical clarity and sharpness.
Best For
1.67 high index lenses are preferred for prescriptions with a sphere (SPH) measuring +/- 7.00 to +/- 9.00 and a cylinder (CYL) of +/- 3.25 to +/- 4.00
Costs
$40 – $130 more than standard lenses* <em>(Price varies considerably but most can be had for $30 or less.)</em>
1.60 High Index Lenses
1.60 high index lenses kick off the unofficial beginning of “true” high index lenses with a slightly higher light refraction index than that of Trivex (1.53) and polycarbonate (1.59).
Additionally, they are lighter than both of those lenses despite only having a marginally larger index than polycarbonate.
Key Features
Up to 10% Lighter & thinner than Polycarbonate lenses.
Up to 20% lighter & thinner than standard CR-39 lenses.
Aspheric design for less lens distortion.
Great optical clarity and sharpness.
Best For
1.60 high index lenses are recommended for prescriptions with a sphere (SPH) of approximately +/- 4.25 to +/- 6.75 along with a cylinder (CYL) measurement of +/- 2.25 to +/-3.00.
Costs
$25 – $40 more than standard lenses*
Polycarbonate Lenses – 1.58 Index
Polycarbonate lenses came about in the 1980’s after the material was developed and used by the aerospace industry in the 1970’s. It has incredible impact resistant abilities making it a great choice for bulletproof glass and fighter jet cockpits among other things. Polycarbonate lenses are the preferred lens for children and adults with active lifestyles because of this.
As mentioned above, they are slightly heavier (10%) than Trivex lenses despite being thinner (10%) than them. Last, polycarbonate lenses have UV protection and are recommended for those with a sphere (SHP) of +/- 4.00 to +/- 6.00 and a cylinder (CYL) of +/- 2.00.
Trivex Lenses – 1.53 Index
Trivex lenses were created by PPG Industries to be a direct competitor to polycarbonate lenses. Like polycarbonate, they are thinner (by 20%) and lighter than standard plastic lenses and offer excellent impact resistance.
Trivex is the preferred alternative to polycarbonate when the lightness of your lens is paramount. Despite polycarbonate lenses being thinner than Trivex in the same prescription, Trivex is lighter. They are about 20% lighter than standard lenses as well and are recommended for a lens sphere (SPH) of +/- 3.00 and below.
Standard Plastic / CR-39 Lenses – 1.50 Index
CR-39 lenses are the standard plastic lenses included from most eyewear retailers today. While they certainly aren’t the clearest, lightest, or thinnest lens, they can get the job done well for a lot of people. However, they are only recommended for more basic prescriptions with a sphere (SPH) correction of approximately +/- 4.00 and below.
If you have a relatively strong to very strong prescription, CR-39 lenses won’t work for you at all as their edges become to thick to fit in any frames with stronger prescriptions. Trying to make them fit can distort or even break your glasses frame. They also aren’t typically available as an aspheric shape but can be modified at an extra cost.
The answer to this question depends mostly on your prescription and a little on your budget. If you genuinely have a strong prescription, high index lenses will be your only chance at near distortion-free vision. They will also be the only way to fit many strong prescription lenses into eyewear frames properly.
After this, high index lenses become more of a desire for performance, style, or clarity. You will see more clearly and be able to use many more frames with high index lenses, but you can also hit a point of diminishing returns. At some point, going to a higher index won’t increase vision performance and will just cost you more money at the end of the day.
If you think you would benefit from high index lenses, we recommend you visit with your local eye optician or one online to discuss lense options.
We almost always say “yes,” but again, this depends on your specific situation. Strong prescriptions will almost certainly need high index lenses to fit into most frames and to ensure minimally distorted vision.
As we discuss in the question above, make sure you are aware of diminishing returns. If you missed the issue discussed above, at some point, you might not experience an increase in vision performance despite going up in lens index. No added gain in performance most commonly occurs when you have a mild to moderately strong prescription but don’t need to the highest index of 1.74. Going past this point only increases cost, not performance or benefit.
The cost of high index lenses starts somewhat reasonably at approximately $20 and can go all the way to $200+ more than standard lenses. Again, prices vary significantly depending on your prescription combined with the exact index you choose, as well as where you decide to purchase them.
You’ll likely find the best prices online, but it’s a good idea to check locally as well.
*While it’s possible to purchase over-the-counter (OTC) reading glasses without a prescription, we still recommend getting an annual eye exam to ensure you are maintaining proper vision health.
Also, note that OTC reading glasses should only be used with a lens magnification of +3.00 or less. Anything stronger and we recommend visiting your eye doctor to get their recommendation before purchasing.
Thoughts, questions, or concerns? We would love to hear from you! Post your comments below, but please keep our site safe and clean for all to enjoy. Any comments posted under Eyewear Genius’ official account are not reviewed or endorsed by any retailers or brands affiliated with the reviewed products unless explicitly stated otherwise.
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High Index Lenses & Glasses – Ultimate Buyer’s Guide 2021
High Index lenses are thinner, stronger, and more versatile than standard eyewear lenses. They are made from extremely durable plastic and are regarded as the best lenses you can get for your prescription glasses. Their key benefits include lighter weights and much thinner lens construction which improves fit and clarity.
What Are High index lenses?
High index lenses work by bending light more efficiently than their conventional counterparts. Referred to as the index of refraction, this is a ratio used to determine the speed at which light passes through a given lens material. Because high index lenses can transmit and bend light more efficiently than standard lenses, they can be made considerably thinner and lighter.
Thinner lenses are especially a considerable benefit for those that are nearsighted (most people), meaning they have lenses that are thinner in the center and get thicker at the edges. With high index lenses, these people can now more easily fit their stronger lenses in the same stylish frames as those with much weaker prescriptions.
High-index lenses are available in a vast range of indices, all of which can be found in the range of 1.53 to 1.74. Lens index is determined by a measurement of light refraction and lenses with a refraction index of 1.70, or higher are up to 50% thinner than standard plastic lenses.
Determining which lens is right for you can be a bit confusing but note that the higher the index number, the thinner and lighter the lenses are. Of course, we always recommend consulting with your eye doctor before selecting a new lens to make sure you are choosing the best lens for your specific needs.
Lens Index Chart: A Visual Comparison
Polycarbonate vs Trivex vs 1.60 vs 1.70 vs 1.74 Lenses
Click on lens type to jump to its features → 1.74, 1.67, 1.60, 1.58, 1.53, 1.50
Featured Topics:
Advantages Of High Index Lenses
Disadvantages Of High Index Lenses
Different Types Of High Index Lenses
– 1.74 High Index Lenses
– 1.67 High Index Lenses
– 1.60 High Index Lenses
– 1.58 High Index Lenses (Polycarbonate)
– 1.53 High Index Lenses (Trivex)
– 1.50 Standard Index Lenses (CR-39)
High Index Lenses FAQ
– Do I Need High Index Lenses?
– Are High Index Lenses Worth It?
– High Index Lens Costs
Advantages of High Index Lenses
There is a lot of “good” to be gained from high index lenses, and if you have a strong prescription, you won’t want to miss out on their many benefits.
Thinner, Lighter, & Stronger
High index lenses come in a variety of indices ranging from 1.53 to 1.74, with “true” high index starting at an index of at least 1.60. At this index level, you will begin to benefit from a significantly thinner lens, as we mentioned briefly above.
In fact, high index lenses of 1.60 or higher typically result in a 25% – 50% reduction in overall lens weight compared to conventional lenses. As a result of the thinner lens, you will benefit from a significantly lighter lens as well.
High index lenses are also known for their superior strength and are second only to polycarbonate in durability and impact resistance.
Again, for those of you that have had strong prescription resulting in thick lenses, this is a real game changer as you will literally be lifting the weight of your glasses off of your face.
More Clarity & Less Distortion
Other benefits include increased clarity and less lens distortion when compared to standard lenses. High index lenses refract light more efficiently than lower index lenses resulting in a much thinner lens overall.
They are also available in an aspheric design which is especially helpful if you are nearsighted. Aspheric lenses are made flatter than conventional lenses allowing for much better clarity with far less distortion. The aspheric design also helps to reduce the “bug eye” look for anyone with a very strong prescription.
Greater Frame Selection
With standard lenses, people with stronger prescriptions may not be able to choose from many frames due to the lens edge being too thick to fit or seat properly. High index lenses create that significantly thinner edge we discussed above which means you can fit your lenses in just about any frame you like.
Disadvantages of High Index Lenses
There is very little to dislike about high index lenses, but there are two key drawbacks that can’t be ignored.
Increased Cost
The most obvious drawback of high index lenses is their cost. Lens cost varies significantly depending on the retailer, but expect to pay anywhere from $25 – $200 more for your index lenses online.
The vast price range is determined partly by the eyewear retailer or brand you choose but can be blamed mostly on the exponentially increasing costs of higher index lenses. Simply put, the larger the index number, the thinner the lens, and the more you can expect to pay.
Additionally, you can expect to spend even more than most online retailers should you decide to go to a brick and mortar optician.
Last, you may also want to avoid high index lenses for your first pair of glasses altogether. Your prescription could frequently change in the early stages resulting in multiple costly lens changes. In some instances, the retailer or your local optician may have a buyer satisfaction policy that protects you from lens changes for a period of days, usually 30 – 60 days.
Increased Lens Reflection
Another critical drawback of high index lenses is their inherent ability to reflect light, as much as 50% more than standard lenses. Thankfully, this is a mostly insignificant issue that can be all but eradicated by the addition of a quality anti-reflective (AR) coating to the lens.
A quality anti-reflective coating will eliminate 99% of reflections making the lenses nearly invisible (good for photographs). The AR coating is also a significant benefit at night as headlight reflections are significantly reduced increasing clarity and sharpness while driving.
Different Types of High Index Lenses
1.74 High Index Lenses
1.74 high index lenses achieve the designation as the thinnest lenses available for sale in the United States under current regulations. They are easily considered the ultimate in lightweight lens technology and provide unparalleled clarity and sharpness along with incredible durability.
1.74 high index lenses can get up to 10% lighter & thinner than 1.67 high index lenses and a whopping 50% lighter & thinner standard CR-39 lenses of the same prescription.
Key Benefits
Best For
Anyone that desires the absolute best in thin, lightweight lens technology. They are recommended for prescriptions with a sphere (SPH) of +/- 9.25 and above, along with a cylinder (CYL) of +/- 4.25 to +/- 6.00.
Costs
$85 – $200 more than standard depending on the retailer, brand, & prescription.
1.67 High Index Lenses
1.67 high index lenses will be the first real dramatic jump into high index lenses for most people. Additionally, this is the most common index of lens used for those with moderate to stronger prescriptions.
They are remarkably thin lenses and remain an excellent choice for anyone seeking comfort paired with sharp, minimally distorted vision. They are up to 20% thinner & lighter than polycarbonate and 40% thinner & lighter than standard CR-39 lenses with the same prescription.
Key Benefits
Best For
1.67 high index lenses are preferred for prescriptions with a sphere (SPH) measuring +/- 7.00 to +/- 9.00 and a cylinder (CYL) of +/- 3.25 to +/- 4.00
Costs
$40 – $130 more than standard lenses* <em>(Price varies considerably but most can be had for $30 or less.)</em>
1.60 High Index Lenses
1.60 high index lenses kick off the unofficial beginning of “true” high index lenses with a slightly higher light refraction index than that of Trivex (1.53) and polycarbonate (1.59).
Additionally, they are lighter than both of those lenses despite only having a marginally larger index than polycarbonate.
Key Features
Best For
1.60 high index lenses are recommended for prescriptions with a sphere (SPH) of approximately +/- 4.25 to +/- 6.75 along with a cylinder (CYL) measurement of +/- 2.25 to +/-3.00.
Costs
$25 – $40 more than standard lenses*
Polycarbonate Lenses – 1.58 Index
Polycarbonate lenses came about in the 1980’s after the material was developed and used by the aerospace industry in the 1970’s. It has incredible impact resistant abilities making it a great choice for bulletproof glass and fighter jet cockpits among other things. Polycarbonate lenses are the preferred lens for children and adults with active lifestyles because of this.
As mentioned above, they are slightly heavier (10%) than Trivex lenses despite being thinner (10%) than them. Last, polycarbonate lenses have UV protection and are recommended for those with a sphere (SHP) of +/- 4.00 to +/- 6.00 and a cylinder (CYL) of +/- 2.00.
Trivex Lenses – 1.53 Index
Trivex lenses were created by PPG Industries to be a direct competitor to polycarbonate lenses. Like polycarbonate, they are thinner (by 20%) and lighter than standard plastic lenses and offer excellent impact resistance.
Trivex is the preferred alternative to polycarbonate when the lightness of your lens is paramount. Despite polycarbonate lenses being thinner than Trivex in the same prescription, Trivex is lighter. They are about 20% lighter than standard lenses as well and are recommended for a lens sphere (SPH) of +/- 3.00 and below.
Standard Plastic / CR-39 Lenses – 1.50 Index
CR-39 lenses are the standard plastic lenses included from most eyewear retailers today. While they certainly aren’t the clearest, lightest, or thinnest lens, they can get the job done well for a lot of people. However, they are only recommended for more basic prescriptions with a sphere (SPH) correction of approximately +/- 4.00 and below.
If you have a relatively strong to very strong prescription, CR-39 lenses won’t work for you at all as their edges become to thick to fit in any frames with stronger prescriptions. Trying to make them fit can distort or even break your glasses frame. They also aren’t typically available as an aspheric shape but can be modified at an extra cost.
High Index Lens FAQ
Do I need high index lenses?
The answer to this question depends mostly on your prescription and a little on your budget. If you genuinely have a strong prescription, high index lenses will be your only chance at near distortion-free vision. They will also be the only way to fit many strong prescription lenses into eyewear frames properly.
After this, high index lenses become more of a desire for performance, style, or clarity. You will see more clearly and be able to use many more frames with high index lenses, but you can also hit a point of diminishing returns. At some point, going to a higher index won’t increase vision performance and will just cost you more money at the end of the day.
If you think you would benefit from high index lenses, we recommend you visit with your local eye optician or one online to discuss lense options.
Are high index lenses worth it?
We almost always say “yes,” but again, this depends on your specific situation. Strong prescriptions will almost certainly need high index lenses to fit into most frames and to ensure minimally distorted vision.
As we discuss in the question above, make sure you are aware of diminishing returns. If you missed the issue discussed above, at some point, you might not experience an increase in vision performance despite going up in lens index. No added gain in performance most commonly occurs when you have a mild to moderately strong prescription but don’t need to the highest index of 1.74. Going past this point only increases cost, not performance or benefit.
High Index Lens Costs
The cost of high index lenses starts somewhat reasonably at approximately $20 and can go all the way to $200+ more than standard lenses. Again, prices vary significantly depending on your prescription combined with the exact index you choose, as well as where you decide to purchase them.
You’ll likely find the best prices online, but it’s a good idea to check locally as well.
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