Higher prescriptions require high index lenses to keep them thin and light. The higher a lens’ index number, the thinner it becomes. High index lenses tend to be very stylish and lightweight and are meant …방문 중인 사이트에서 설명을 제공하지 않습니다.Thickness difference between the two indexes will be negligent but the weight of the lenses will be noticeable. If your wallet permits , spring for the 1.67 index lenses . My extra is not nearly as high as yours and I prefer 1.74 index lenses simply for their weight .1.61 vs. 1.67 vs. 1.74 High Index Lenses. 1.61 High Index Lenses. Moderate Prescription Strengths: Ideal for those with mild prescriptions (less than +/- 2.00) Thinner and Lighter: Offers a significant reduction in thickness and weight compared to standard 1.50 CR39 lenses.Mar 19, 2024 · Assuming that light travels from air to glass, the angle of incidence is 30°, and the angle of refraction is 20°. To calculate the refractive index, follow these steps: Identify the refractive index of air: n ₁ = 1. Modify Snell's law to find the refractive index of glass: n ₂ = n ₁sin (θ₁)/sin (θ₂). Enter data: n ₂ = 1×sin (30 ...We firmly believe the prices of our prescription lenses offer the best value when compared with other online retailers and high street opticians - see for yourself below. Lens Guide ... High Impact (1.56 Index) - Clear Lenses. £70.00. 1.59 D28 Polycarbonate - Clear Lenses. £50.00. 1.60 D28 Flat Top - Clear Lenses. £100.00 + Tints.Confused about Trivex & High Index. I ordered a pair of glasses from Zenni for the first time, and while thrilled with the frames, I simply couldn't see out of the lenses - especially while driving at night. I took them to my optometrist (who does not sell eyewear), and my heart sank when he told me that both the lenses & my … Without knowing PD of you or the frame it is hard to gauge but most people are correct I feel in saying 1.6 is fine and 1.67 would come out a bit nicer. If you were my patient I'd tell you 1.6 and explain that the difference is about a 20%reduction in thickness (again depending on pds). Aug 31, 2016 · GhostBond. • 8 yr. ago. 1.5 has the least distortion and abberation of all the lens materials - it's the best (abbe value). I have a way way worse prescription than you do, and still do 1.5 because 1.67 was awful. So since you have a lower prescription I'd definitely say 1.5. It's also called CR39. 1. r/glasses.The Consumer Price Index is the best known indicator of inflation. Learn 13 facts about the Consumer Price Index to better understand the role it plays in economics. The Bureau of ...Thinner and lighter than our basic lenses, high-index lenses are recommended for those with combined Rx powers over -3.00/+2.00. High-index lenses have reduced edge thickness for nearsightedness and …An easy way to remember this: the higher the index, the thinner your lens will be. Thin – 1.61 Hi-Index (Basic) This lens material is suitable for prescriptions from +2.00 to -4.00 and astigmatism correction of -3.00 or less. 1.61 Hi-Index is on average 25% thinner than CR 39. Thinner – 1.67 Hi-Index (Better)Versus the 1.6 lens could be more optically clear, but will undoubtedly be heavier and not impact resistant . The thinnest option available and designed for people that have the best prescriptions, 1.74 high index lenses are the optimal choice should you have a high prescription. 1.67 high index lenses are incredibly thin and light, …Aug 31, 2016 · GhostBond. • 8 yr. ago. 1.5 has the least distortion and abberation of all the lens materials - it's the best (abbe value). I have a way way worse prescription than you do, and still do 1.5 because 1.67 was awful. So since you have a lower prescription I'd definitely say 1.5. It's also called CR39. 1. r/glasses.I know that high-index is supposed to make the lens thinner, but I was wondering if there would be a noticeable difference between 1.57 (which is free) and 1.67 ($35 additional charge). Also someone else mentioned that people with stronger prescriptions should stay away from rimless or partial rim glasses as well as big …Do you know the differentiation between various lens flash? Go this article to learn more about books of refraction measurements for my eyeglasses. x Blue Light Blocking Glassware BOGO 40% OFF BOGO 40% OFF. WOMEN. Women's Glass. All Women's Glasses. Cat-Eye Eyeglasses. New Arrivals. Best Sellers. $5. ...Thin & Light. 1.56 index. Thin and Light 1.56 index lenses are up to 15% thinner an lighter compared with our standard 1.5 index lenses, these also include anti-reflective coating, anti-smudge, dust repellent and water repellent treatments as standard. Recommendations. Prescriptions with sphere values from +/-3.00 to +/-3.75.See the difference between high index and Trivex lenses - and find out which is best for you!1.5 Standard. 1.56 Mix-Index. 1.57 Thin and Light Index. 1.59 Standard Polycarbonate and High Index. 1.74 High Index Lenses are the thinnest and lightest. …The most common high index options are 1.61, 1.67, and 1.74. These numbers represent the refractive index of the lens material. If your prescription power is …Nov 23, 2022 · From high-index and polycarbonate lenses, there's a lot to consider when choosing a lens type. That’s why we created this guide on high-index vs. polycarbonate lenses. Focusing on these two commonly used lens materials, you’ll learn their pros and cons to decide which eyeglass lenses you should choose. High-Index vs. Polycarbonate Lenses 101 Feb 26, 2020 ... Generally speaking, high-index is best suited for higher (more severe) prescriptions. Anything above a minus 5 and above a plus 3 is considered ...polycarbonate or high-index MR-7 or MR-10, 1.60 or 1.67 lenses. Your prescription is very mildly common, so unless you are extremely concerned with edge thickness or eye minification, then you will be just fine with nothing higher than 1.61. You will see very little difference in thickness between 1.61 and 1.67 in your correctionBut then you'd know if polcarbonate works for you. But if you consider the lifetime cost of new polycarbonate lenses versus high index (say, $100 difference, new glasses every 4 years, live for another 40 years = $1000), it's not that much more money for high index (depending your your parameters for that equation).It really depends on the size of the frame you want to buy. Smaller frames will show less of a difference between the two materials, and with a larger frame you will see a difference. 1.74 has a crappy Abbe value and produces visual distortion. Also, 1.74 is actually thicker than 1.67. 1.67 is better overall.The New York Marriage Index is a valuable resource for individuals looking to research their family history or gather information about marriages that have taken place in the state...I'm buying glasses for the first time from Zenni and 1.74 high index lenses are recommended for my prescription (-12.50/-13.25). They also have UV/blue light blocking lenses they call Blokz, but they only come in a 1.67 high index lens. I get migraines at least once every week or two and become sensitive to light during …High index lenses bend light more effectively than other types of lenses because of their higher index of refraction, so Lensmart offers 1.61, 1.67 and 1.74 high index lenses. You can easily find the best frame for lenses and enjoy the perfect fit. With lightweight high index lenses, you can have clear vision without the "coke bottle" look.The most common types of high-index lenses have refractive indexes of 1.61, 1.67, and 1.74. What’s the Difference Between High-Index and Polycarbonate …People with diabetes and others who have been advised to follow a low-glycemic index diet need to make sure the foods they eat don’t increase blood sugar by too much. This guide wi...Associations between anthropometric parameters (body mass index, ... The prevalence of newly diagnosed HUA was higher in men than in women (19.46% vs 11.34%, p<0.05). Multivariate liner regression showed that BMI, WC and WHR were positively correlated with serum uric acid.oniononon. • 5 yr. ago. The power in your left lens is that high that I'd have gone for 1.67 as well. I have five pairs of glasses with 1.6 index lenses and one pair of sunglasses with …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.It’s safe to say that every investor knows about, or at the very least has heard of, the Dow Jones U.S. Index. It is an important tool that reflects activity in the U.S. stock mark...Feb 27, 2019 · Trivex lenses about 10 percent lighter than polycarbonate lenses. Optics - central. Trivex lenses have less internal stress and may produce sharper central vision than polycarbonate lenses. Optics - peripheral. Trivex lenses have a higher Abbe value and may produce sharper peripheral vision with less chromatic aberration than polycarbonate lenses.Feb 26, 2020 · High-index materials are denser than lower-index polycarbonate, which means they result in thinner lenses in order to refract light accurately. For example, if a polycarbonate lens requires 2 millimeters of material to refract light, high-index may only need 1 millimeter. Translation: high-index is the smart option for stronger prescriptions. Certain high index materials are available with the coating, but the nature of high index lenses often precludes the availability of transitional lenses. Not all manufacturers combine the two formats – especially on the higher-end high index materials like 1.80 or 1.90 glass lenses. If you want transition high index lenses you’re more ... ZEISS Single Vision SmartLife lenses. Supported by ZEISS SmartView Technology, based on applied research of today’s lifestyle, visual behaviour and individual age-related visual needs. The first ZEISS single vision lenses optimised for both distance and near vision. Available in: Plastic 1.5, Plastic 1.6, Plastic 1.67, Plastic 1.74, Trivex 1.53.If you have a prescription that is +4.75/-6.75 or below, you’ll benefit from the thinness of a 1.67 high-index lens. Strong prescriptions that are +5.00/-7.00 or above will work best with a 1.74. When you have a really strong prescription, a 1.74 high-index lens will be the thinnest option.High index 1.67 Single Vision lenses can be great for stronger prescriptions because they're thin and light instead of thick and bulky.May 18, 2023 ... Standard lenses are at an index of 1.50 while the highest options are between 1.74 and 1.90. The stronger your prescription, you can choose ...High index 1.67 Single Vision lenses can be great for stronger prescriptions because they're thin and light instead of thick and bulky.Mar 19, 2024 · Assuming that light travels from air to glass, the angle of incidence is 30°, and the angle of refraction is 20°. To calculate the refractive index, follow these steps: Identify the refractive index of air: n ₁ = 1. Modify Snell's law to find the refractive index of glass: n ₂ = n ₁sin (θ₁)/sin (θ₂). Enter data: n ₂ = 1×sin (30 ... Thinner and lighter than our basic lenses, high-index lenses are recommended for those with combined Rx powers over -3.00/+2.00. High-index lenses have reduced edge thickness for nearsightedness and reduced center thickness for farsightedness. Choose from 1.61, 1.67 or 1.74 high index lenses. All Zenni high-index lenses are made with MR™, a ... Are you a classic car enthusiast in search of the iconic 67 Chevelle? Look no further. In this ultimate guide, we will provide you with valuable tips and tricks to help you find th...I'm buying glasses for the first time from Zenni and 1.74 high index lenses are recommended for my prescription (-12.50/-13.25). They also have UV/blue light blocking lenses they call Blokz, but they only come in a 1.67 high index lens. I get migraines at least once every week or two and become sensitive to light during …Safety glasses with photochromic lenses cost between $40 and $220 a pair. Sunglasses with photochromic lenses cost between $75 and $400 a pair. Getting photochromic technology added to a pair of prescription eyeglasses usually adds between $100 and $400 to the total cost of those glasses. In many cases, …Higher prescriptions require high index lenses to keep them thin and light. The higher a lens’ index number, the thinner it becomes. High index lenses tend to be very stylish and lightweight and are meant …The most common high index options are 1.61, 1.67, and 1.74. These numbers represent the refractive index of the lens material. If your prescription power is …Pros and Cons of 1.67 High Index Lenses. Pros: Thinner and lighter than 1.61 lenses; Suitable for individuals with stronger prescriptions; Aesthetically pleasing; Cons: Higher cost compared to 1.61 lenses; May not be suitable for all frame styles; …Actually, there is, and it just might be a pair of 1.67 High Index Polarized Lenses. High index lenses are made from a special composite material that allows them to be much thinner and lighter than regular glasses. 1.67 high index is the most common and least expensive high index material available. They fit a wide …Status code 61 has several different possible meanings depending on jurisdiction. According to The Oregonian newspaper, the police code signal 61 means “subject in custody” in the ...방문 중인 사이트에서 설명을 제공하지 않습니다.Aug 31, 2016 · GhostBond. • 8 yr. ago. 1.5 has the least distortion and abberation of all the lens materials - it's the best (abbe value). I have a way way worse prescription than you do, and still do 1.5 because 1.67 was awful. So since you have a lower prescription I'd definitely say 1.5. It's also called CR39. 1. r/glasses.They currently come in indices of 1.61, 1.67, and 1.74. All three lenses are made with similar materials, so the choice of the index comes down to your prescription strength. A 1.67 high-index lens is best for +7.00/-9.00 or above. It can even be a good choice for people with low prescriptions who want the additional lens …Apr 8, 2022 · 1.67 Ultra High Index Ultra-High index lenses are made of a dense material, which allows them to block 100 percent of UV rays and resist scratches . They are perfect for thin eyewear frames or those with a strong prescription of SPH correction of +/- 7.00 and +/- 9.00, and CYL correction of +/- 3.25 and +/- 4.00. Jul 7, 2022 · 1. Trivex lenses have an index of 1.53 which is lower than high index plastic having 1.67 to 1.74. The higher the index, the more lightweight and thinner the lens will be. 2. In terms of resistance to scratch, both lenses are the same. 3. Trivex lenses are more impact resistant than high index lenses.Both 1.67 and 1.74 high-index lenses can accommodate strong prescriptions. The difference is in the thickness. 1.74 high-index lenses are up to 10% thinner than 1.67 high-index lenses. As a reference, 1.67 high-index lenses are recommended for strong prescription with an SPH correction between +/-7.00 and +/ … However, presenting various reasons for why you should and shouldn’t buy 1.67 high index lenses vs standard CR-39 plastic lenses should help those who are undecided: When 1.67 High Index Lenses Make Little Difference. If CR-39 lenses for your prescription level aren’t excessively thick or heavy, then don’t get 1.67 high index lenses. Photochromic 1.67 Transitions VI. In response to customer complaints of slow-transitioning lenses, one of these improvements resulted in the release of Transitions® VI, a photochromic coating that allows up to a 40% faster shift in tint. This upgrade to standard transitional lenses also provides better UV protection … So I figured I'd order another pair from Zenni and see how I like them. The thing is, I'm torn between the 1.61 and 1.67 high index range. My right eye is still safely in that "1.61 is fine" range, but the left eye obviously requires a thicker lens. Because they wouldn't be my day-to-day glasses, however, I'm leaning towards getting the cheaper ... Generally, lenses with an increased index of refraction will be thinner than lenses with less index. The refractive index of high index plastic lenses ranges from 1.53 to 1 1.74. Those in the range of 1 1.53 to at least one 1.59 are about 20% thinner than regular plastic lenses, whereas 1.74 high index lenses… Craft breweries have gained immense popularity in recent years, offering beer enthusiasts a wide range of unique and flavorful options. One such brewery that stands out from the cr...I'm buying glasses for the first time from Zenni and 1.74 high index lenses are recommended for my prescription (-12.50/-13.25). They also have UV/blue light blocking lenses they call Blokz, but they only come in a 1.67 high index lens. I get migraines at least once every week or two and become sensitive to light during …Jul 4, 2020 ... If u want to make these type of spectacles then whatsapp your power and Contact through whatsapp 9818540760. Link to watch special videos ... Standard index 1.50 (also known as CR-39) Mid-index 1.57. High index. 1.61, 1.67, 1.74. The larger the number, the thinner and lighter the lens, but the higher the cost. 1.61 is up to 20% thinner than standard lens. 1.67 is up to 30% thinner than standard lens. 1.74 is up to 40% thinner than standard lens. Sponsored by FinanceBuzz. The 1.61 High-Index is an extra $35, and sounds more brittle and less scratch resistant. Prescription L: -1.25 sph, -0.75 cyl, 180 axis R: -1.75 sph, -0.75 cyl, 180 axis I also saw one old comment claiming "1.56 is a s*** material that you will usually only find at cheap online retailers" - not sure if true. Thanks ...I have a +4.25 prescription, should I get 1.67 or 1.74 index lenses for glasses? Would there be any noticeable difference in thickness? I'm also concerned about the distortion/warping - my current pair is just a standard lens (not high-index) and there is a noticeable warping effect when looking at my eyes from a side angle, I think this is due to how thick the …Versus the 1.6 lens could be more optically clear, but will undoubtedly be heavier and not impact resistant . The thinnest option available and designed for people that have the best prescriptions, 1.74 high index lenses are the optimal choice should you have a high prescription. 1.67 high index lenses are incredibly thin and light, … Certain high index materials are available with the coating, but the nature of high index lenses often precludes the availability of transitional lenses. Not all manufacturers combine the two formats – especially on the higher-end high index materials like 1.80 or 1.90 glass lenses. If you want transition high index lenses you’re more ... 1.61-1.67 index – the first upgrade level considered “high index.”. Lenses produced from material in this range can reduce thickness by up to 30% in comparison to 1.50 lenses. 1.74 index – the flattest and thinnest lens available in plastic. Lenses produced from 1.74 material can reduce thickness by up to 45% in comparison to 1.50 lenses. Generally, lenses with an increased index of refraction will be thinner than lenses with less index. The refractive index of high index plastic lenses ranges from 1.53 to 1 1.74. Those in the range of 1 1.53 to at least one 1.59 are about 20% thinner than regular plastic lenses, whereas 1.74 high index lenses… One of the first successful 1.6 high-index lenses introduced was made from MR-6 material (1987). With an index of 1.594, Abbe of 36 and specific gravity of 1.43gms/ cc3, it made for a thinner and lighter lens. This material also had the added benefit that 100 percent UV absorption was built in.Hi-index 1.61: Prescription power between +/- 3.00. Hi-index 1.67: Prescription power between +/- 3.00 ~ +/- 5.00. Hi-index 1.74: Prescription power …1.67 High Index. The 1.67 High-Index lenses are 30% thinner than 1.50 Standard Index lenses with the same prescription. For higher prescriptions, this lens material and index works well due to its reduced weight and edge thickness. 1.74 High Index. 1.74 High-Index lenses are the thinnest and lightest lenses you can buy from …Dec 13, 2019 ... Lensa kacamata dengan ukuran power sama, frame yang sama tetapi dipasangi lensa beda index 1.56 vs 1.67. Bagaimana hasilnya?1.67 High Index 1.67 high-index lenses surpass in thinness and lightness when compared to 1.61 high-index lenses. It helps with eye distortion caused by stronger prescriptions and is ideal for individuals with an SPH correction between +/- 7.00 and +/- 9.00, and a CYL correction between +/- 3.25 and +/- 4.00.A lens is high-index when the refractive index exceeds that of plastic or glass, as are used in most traditional materials. The general range of refraction is around 1.53 to 1.74. When the refractive index is 1.7 or more, the lens is usually about 50% thinner than it’s glass or plastic counterpart would be.Knowing The Difference Between 1.50 And 1.74 Table of Contents hide 1 Knowing The Difference Between 1.50 And 1.74 1.1 What does lens index mean? 1.2 1.50 Standard Index 1.3 1.56 Mid-Index 1.4 1.59 Polycarbonate 1.5 1.61 High Index 1.6 1.67 High Index 1.7 1.74 High Index 1.8 What factors should I consider when choosing …If you’re a classic car enthusiast, there’s no doubt that the 67 Chevelle holds a special place in your heart. This iconic muscle car is known for its sleek design, powerful engine...High Index "necessary" for these kinds of frames? I've been trying to find semi-large circular lenses to little success, though I did find one pair that I actually liked. However I'm worried that my high prescription (-5.50 right, -5.25 left) might benefit more from a higher index. (1.61 vs 1.67). Though that makes the lenses about …1.67 High Index 1.67 high-index lenses surpass in thinness and lightness when compared to 1.61 high-index lenses. It helps with eye distortion caused by stronger prescriptions and is ideal for individuals with an SPH correction between +/- 7.00 and +/- 9.00, and a CYL correction between +/- 3.25 and +/- 4.00.Thin lenses are high index lenses which pack more prescription power without being too thick. Here's how to know if you need them or not. Free Returns Blog Offers 24 Hr Dispatch (Holiday Schedule) E-Gift Card +44 (0) 161 312 5767 Help Login Register. Glasses. Style. Clear Glasses; Pilot Glasses ...We firmly believe the prices of our prescription lenses offer the best value when compared with other online retailers and high street opticians - see for yourself below. Lens Guide ... High Impact (1.56 Index) - Clear Lenses. $75.83. 1.59 D28 Polycarbonate - Clear Lenses. $54.17. 1.60 D28 Flat Top - Clear Lenses. $108.33 + Tints.If you’re moderately, or very short-sighted you’ll benefit from thinner lenses as the edge thickness of your lenses will be more visible. Lenses with a refractive index of 1.6 are ideal for prescriptions where the – value of your SPH prescription is between -2.50 and -4.00. Between -4.00 and -6.00 we’d recommend a lens with a refractive ...Dialing *67 directly before dialing a phone number deactivates caller identification, or caller ID, and the caller ID of the person you are calling will read “private number” inste...If you want transition high index lenses you’re more likely to find them at the lower end of the index spectrum. 1.67 index lenses, for instance, are often available with photochromic lenses. While on the subject, a bit of clarification on terminology is probably in order. “Transition” and “Photochromic” are interchangeable terms.
3 days ago · Birefringence is a measurement of the difference between the two refractive indices in gems that are doubly refractive, and it ranges from a low of .003 to a high of .287. The following chart lists the refractive indices for 215 varieties of gemstones. Refractive Index Chart of all Gemstones Gemstone. Business around me
The higher that number, the thinner the lens will be even with the strongest types of prescriptions. And that is the basic difference between 1.67 and 1.74 high index lenses: the latter is simply thinner, and lighter, than the former. Lenses with a refraction index of 1.7 or higher are at least 50 percent thinner than those with a regular index. 방문 중인 사이트에서 설명을 제공하지 않습니다.Here are the recommendation. If your power is around -2.00, choose 1.56 index, it will be around 3mm. For power around -4.00, choose 1.61 index, it will be around 3 to 4mm. If your power is around -6.00, choose 1.67 index , it will be around 4 to 5mm. For power more than that, choose the thinnest lens, 1.74 index. It will be around 5mm to 8mm.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.The prime numbers less than 100 are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89 and 97. A prime number is any number that is only di...People with diabetes and others who have been advised to follow a low-glycemic index diet need to make sure the foods they eat don’t increase blood sugar by too much. This guide wi...Blue Light Glasses. Customize your Blokz ® blue light blocking glasses with lenses starting at just $16.95, and experience exceptional eye protection tailored to you. In today's digital world, screens, artificial light, and the sun are unavoidable. But you can defend your eyes against excessive blue light exposure with Blokz ® lenses.In the world of academic publishing, it is crucial for publishers to keep track of the impact and reach of their published work. This is where Scopus Citation Index comes into play...Knowing The Difference Between 1.50 And 1.74 Table of Contents hide 1 Knowing The Difference Between 1.50 And 1.74 1.1 What does lens index mean? 1.2 1.50 Standard Index 1.3 1.56 Mid-Index 1.4 1.59 Polycarbonate 1.5 1.61 High Index 1.6 1.67 High Index 1.7 1.74 High Index 1.8 What factors should I consider when choosing …In the world of academic publishing, it is crucial for publishers to keep track of the impact and reach of their published work. This is where Scopus Citation Index comes into play...Aug 10, 2019 ... These are the same frames and same Rx(-17) with 1.56, 1.67, 1.74 index lenses.Frame size and shape is going to have a bigger effect on thickness than index. The difference between 1.60 and 1.67 is going to be minimal, most likely less than a millimeter. 1.67 will cost more and have more abberations. Unless the frame is huge and your eyes are narrow set 1.60 would most likely better. That said I have fit -10s in trivex ...In this section, we will show you the differences between 1.67 high index lenses and 1.74 high indexes. 74 high index lenses are thinner and lighter than 1.67 high index lenses. 74 high index lenses are expensive than the 1.67 high index lenses. Both 1.67 and 1.74 high index lenses can reduce the eye distortion caused by strong …oniononon. • 5 yr. ago. The power in your left lens is that high that I'd have gone for 1.67 as well. I have five pairs of glasses with 1.6 index lenses and one pair of sunglasses with …Sep 8, 2020 · For many wearers, this can make the cost of eyewear prohibitive. At JINS, we offer high index lenses of 1.60 to 1.74 free of charge (availability varies). 2. Durability. High index lenses can be more brittle than their traditional counterparts and may also be more prone to scrapes and scratches.1. Higher satisfaction declared by wearers compared to premium clear lenses. Transitions Optical, Quality of Vision & Vision Experience Test, U.S. 2019, (N=146) - From UV and blue-violet light compared to premium clear lenses.Based on achieving the highest weighted composite score among main everyday photochromic lenses across measurements of …Thickness difference between the two indexes will be negligent but the weight of the lenses will be noticeable. If your wallet permits , spring for the 1.67 index lenses . My extra is not nearly as high as yours and I prefer 1.74 index lenses simply for their weight ..