High Index Lenses
High-index lenses are thinner and lighter than standard lenses and are a great option for anyone with a stronger prescription. They reduce bulk and make your glasses look more stylish than traditional alternatives.
According to research, around 150 million people living in America have refractive errors in their vision. Incoming light doesn't bounce off their natural lens correctly, causing visual distortion leading to farsightedness, nearsightedness, and astigmatism.
High-index lenses correct these without any of the bulk of traditional lenses. They look great and reduce the edge thickness of frames – perfect for anyone on a strong prescription.
The Refractive Index
The refractive index is a measure of a lens's ability to bend light given its thickness. Lenses higher on the index can be thinner, hence the term "high index lenses."
Lenses' material determines their refractive index. Manufacturing methods also play a role.
At EyeGlasses.com, we offer a range of high-index lenses made from various materials, allowing you to find an option that's perfect for you.
Glass offers the highest visual clarity. However, its refractive index is only around 1.52. You can still use glasses lenses for stronger prescriptions, but the result will be thick glasses.
Here are some alternative lens types you can choose from when you come to us, depending on your prescription:
CR-39 Plastic Lenses
CR-39 lenses have a refractive index of around 1.50. And while this isn't as high as some other materials in this list, it is still good enough for most prescriptions. Regular plastic lenses are low-cost and offer exceptional optic quality but may be thick for anyone with stronger glasses prescriptions.
Polycarbonate lenses are the next level up, offering a refractive index of around 1.59 (depending on which you choose). As such, they can be thinner than plastic lenses for a given prescription. Patients also choose polycarbonate lenses because they are compatible with anti-reflective coatings, UV protection, and scratch-resistance technologies.
With that said, if you choose a polycarbonate lens with a low refractive index, those on higher prescriptions may still have to put up with thick eyeglasses.
Trivex is a type of proprietary polycarbonate lens with a refractive index of 1.53. You typically find them in rimless glasses with thicker lenses, though they can come with frames, too. Trivex lenses are thinner, lighter, and more comfortable than regular versions.
High Index Lenses
High-index lenses are made of special plastic and come in several types, including 1.67 and 1.74.
1.67 high-index lenses are suitable for people with prescriptions ranging from +/-5.00 to +/- 8.00. This means that even if you have a particularly strong prescription, you can still get lightweight, discreet glasses.
1.74 high index lenses are the thinnest lenses available and suitable for stronger prescriptions over +/- 8.00. They are a premium option but also a godsend for anyone with strong prescriptions.
As with regular polycarbonate lenses. high-index lenses can be scratch resistant and have anti-reflective coatings. They can also come with UV resistance, making them just as versatile as conventional lenses.
How Much Of A Difference Is There Between 1.59, 1.67, And 1.74 High Index Lenses?
Most polycarbonate lenses have a refractive index of 1.59. This figure means that they can be around 10 percent thinner than other lenses, including glass. By contrast, 1.67 high-index lenses are about 30 percent thinner and lighter, and 1.74 single-vision lenses are 35 percent thinner for the same prescription strength.
In reality, though, high-index lenses often wind up looking similar to regular lenses when fitted to frames. That's because they are mostly used by people with the strongest prescriptions, so they need more material to bend light. Of course, even if you have a lower prescription, you can still explore upgrading.
Why People Choose High Index Lenses
Here are some of the many benefits of high-index lenses:
They Are More Discreet
Thicker eyeglass lenses are effective in refracting light, but they can make some people with stronger prescriptions feel self-conscious. When eyeglasses are too thick, they can look geeky.
For that reason, many people choose higher-index lenses. 1.67 and 1.74 varieties can be significantly thinner than conventional alternatives, reducing the need for thick frames.
They Are More Impact Resistant
High-index lenses are also more impact resistant. Thicker lenses tend to be less secure within the frame, making them more likely to pop out. Thinner lenses, on the other hand, are much more likely to stay in place, even when dropped.
They Reduce The Magnifying Effect Of Your Eyes
Thick glasses lenses can make you look bug-eyed where your eyes appear larger than normal. However, high-index lenses can reduce this effect by bending light differently. Hence, these glasses give you a more natural appearance, closer to what you look like when you don't wear glasses.
They Make Your Glasses Lighter
High-index lenses are also lighter because they use less material. They are considerably more comfortable when balancing on the bridge of your nose.
The difference between high-index lenses and traditional farsightedness lenses is considerable. High-index lenses are incredibly light while traditional lens material can be quite heavy. The same is true for nearsightedness lenses. High-index lens options can cut the weight of standard plastic lenses, making them more comfortable for long-term use.
They Can Be Progressive
Progressive lenses are ideal for people who want to combine multiple prescriptions into a single pair of glasses. Power varies across the surface of the lens continuously, helping the wearer to see things at a distance and up close more clearly.
Advances in technology mean that you can now get progressive high-index lenses. These offer the benefits of both, giving you thinner and lighter lenses without having to invest in multiple prescriptions.
They're Extremely Durable
High-index lenses are also extremely durable. Thanks to their polycarbonate construction, they tend to last longer than other lenses, including those with a lower index. Anti-scratch properties mean that they are perfect for anyone who leads a busy, adventurous life.
They Can Fit Into Practically Any Frame
People with lower prescriptions can use virtually any frame. But, historically, those on higher prescriptions had less choice. That's because many frames cannot accommodate thicker lenses.
Again, thin lenses can help. Compared to other plastic lenses, they are considerably narrower, letting them fit into more frames, including rimless options.
Are There Any Downsides To High Index Lenses?
There are some compromises you make when you choose high-index lenses compared to lower-index lenses.
First, they should always be used with anti-reflective coating, which adds to the expense.
Second, high-index lenses cost more than conventional alternatives. That's because the technology that goes into making them is significantly more advanced. They also use more expensive resins. People are willing to pay the premium, though, because of the benefits they bring.
Third, high-index lenses are not suitable for all prescriptions. You will need to check with your eye doctor whether they are the right choice for you.
Lastly, high-index lenses tend to be more reflective than standard glasses. Therefore, they may not be suitable for the beach or if you regularly drive at night. Anti-reflective coating is available so if you are worried about this, get in touch with a member of our team.
How To Choose High-Index Glasses
Choosing high-index glasses is much simpler than you might think.
First, you'll want to decide whether it is worth the extra cost. While high-index lenses are great for people with prescriptions of =/-6.00 or more, not everyone needs them. If you are on a lower prescription, the benefits will be marginal compared to regular plastic lenses. Remember, you can always choose slightly thicker high-index lens material if you want to.
Next, you'll want to consider the weight. Those on high prescription lenses may want to make the switch to high-index lenses since they can be significantly lighter and more comfortable than standard approaches. Weight can reduce for people on lower prescriptions, but not by much.
Lastly, you'll want to consider how important aesthetics are to you. If you are concerned about the way your current eyeglasses make you look, then you might want to consider 1.67 or 1.74 as an alternative.
Get High Index Lenses Today
If you're interested in experiencing some of the benefits of high-index lenses yourself, then we're here to help. At EyeGlasses.com, we stock an enormous range of high-index glasses compatible with hundreds of frames. Our lenses are made using the latest technology, giving you lighter options you can wear all day. You should notice significant improvements over lower index lenses once you start wearing them.
High Index Lenses FAQs
Are High Index Lenses Worth It?
For most people, most of the time, high-index lenses are worth it, particularly those on strong prescriptions. However, if you're not sure whether they are the right choice for you, talk to an eye doctor. At EyeGlasses.com, we can guide you in your decision-making and help you find the perfect lens thickness for you.
What Is High Index Lens Material?
High-index lenses are made of polycarbonate, a type of plastic. This material has a special structure that bends light more efficiently than regular glass or plastic lenses.
Are High Index Lenses Available With UV protection?
Some high-index lenses come with coatings that provide near-100 percent protection from ultraviolet radiation. Most high-index lenses have UV protection built into them, but you will need to discuss the specifics of each model with your eye doctor.
Do High Index Lenses Make Your Eyes Look Smaller?
High-index lenses will make your eyes look smaller compared to conventional glass lenses if you are on a strong prescription. The higher the lens index, the greater this effect will be.
What Lens Thickness Should You Get?
Lens thickness ultimately depends on your lifestyle. Thicker lenses tend to be the most affordable, but they can be uncomfortable if they are too heavy. Thinner lenses are stylish and lightweight but they come at a higher cost.
Most people. with prescriptions under =/-6.00 choose a lens index of 1.59 or less. However, if your prescription is over +/- 8.00, then you might want to choose lens thicknesses of 1.67 or higher.
Do I Need To Measure My Pupillary Distance For High Index Lenses?
Even if you wear high-index lenses, you will still need to measure the distance between your pupils.
What Is A Good Weight For High Index Lenses?
High-index lenses do not come in standard weights. Each manufacturer has a different process, so their lenses are different. Changes in weight won't impact your vision, but they will affect comfort.
If you would like to know more about the weight of your high-index lens, contact us at EyeGlasses.com for assistance.
Why Do Higher Index Lenses Cost More?
High-index lenses cost more because of the materials they contain. Most are made of polyurethane resin which is more expensive to work with. Standard polycarbonate lenses (and plastic ones) are substantially cheaper because they come from readily available materials.
How Many Different Types Of Thin Lenses Are There?
Most optometrists, opticians, and eyesight professionals will cite 1.59, 1.67, and 1.74 as standard intervals on the lens index. However, there are several others.
1.5 index lenses are conventional single-vision lenses and are usually for people with prescriptions of +/-2.00 or less.
1.57 is another standard, usually reserved for those with moderate prescriptions of +/-3.00 or below.
Then there is the 1.6 index lens. This option is for people with stronger prescriptions who want their glasses to look extra thin. Get them if your prescription ranges from +/-2.25 to 3.00.
At present, 1.74 index lenses are the thinnest available and suitable for those on the highest prescription.
Author of this article:
CEO of Eyeglasses.com, which he founded in 1999. For over twenty years, he has educated consumers, improved their vision choices, and reduced costs in eyewear. Mark authored The Eyeglasses Buying Guide, the most comprehensive and best-selling glasses buying guide in the world.
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