Starting with 1.61 vs 1.67 high index lenses — the 1.67 lens is extremely thin whereas despite still being stylish, the 1.61 lens is extra-thin. The 1.67 lens is a great choice for extra-strong prescriptions. A thin prism is made of a material having refractive indices 1.61 and 1.65 for red and violet light. The dispersive power of the material is 0.07. It is found that a beam of yellow light passing through the prism suffers a minimum deviation of 4.0 ∘ in favourable conditions. Calculate the angle of the prism.Dec 6, 2021 · 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 prescriptions, 1 ... 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 benefits mentioned above. If you have a prescription that is +4.25/-6.75 or below, you’ll benefit from the thinness of a 1.61 high index lens. 1.74 Strong Index. 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.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...Our 1.74 high index lenses are offered at a more affordable price with a long list of value adds: anti-scratch, and 100% UV protection. Available at $69.95. Our 1.74 high index digital free form lenses use leading technologies in the eyeglasses market. Now at $79.95. Our 1.74 digital free form progressive (no-line, multi-focal) lenses …Feb 5, 2020 · The Blokz by Zenni (starting at $17 plus frame cost) are virtually clear lenses for all-day, everyday use, designed to protect your vision from the blue light emitted from our digital devices that ...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.Nov 25, 2020 · A high-index lens may be recommended if your optical prescription is above 2.00 diopters. High-index lenses have a refractive index above 1.50— ranging from 1.53 to 1.74. The image below compares the lens thickness of a regular plastic lens (1.50) to the most commonly prescribed high-index lenses. Note: The higher the refractive index, the ... 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 ...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, … 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. 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 ...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 ...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 …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 +/ … 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. 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… Jan 25, 2022 ... Have a strong prescription? High index lenses may be for you. SportRx breaks down the pros and cons, and if they're right for your ...As for 1.67 high index lenses specifically, they are 20 percent thinner than polycarbonate lenses with the same prescription. With these basics in hand, we arrive at the main …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.This guide discusses everything you need to know concerning the lens index and 1.57 mid index lenses, including standard or mid-index lenses, high index lenses vs. polycarbonate, and much more. 1.61 high-index lenses offer an ultra-thin option for all those looking for a modern, stylish look. Polycarbonate lenses get a lot of press because they’re great for several specific uses, but let’s not discount the value of sleek, slender, and clear 1.67’s. High index plastic tends to have a greater visual clarity and, of course, a thinner profile than polycarbonate which only has a 1.59 index. If you’re not a child and don’t have ... 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 …Starting with 1.61 vs 1.67 high index lenses — the 1.67 lens is extremely thin whereas despite still being stylish, the 1.61 lens is extra-thin. The 1.67 lens is a great choice for extra-strong prescriptions.A 3.67 GPA is equal to an “A” letter grade or being in the 91st or 92nd percentile. GPA stands for “grade point average” and represents the average grade of all the coursework a st...May 27, 2009 · soft for a drill mount application, so you would have to choose a. 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. 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...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 …Jul 5, 2022 · 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 Payne Glasses. OD: -2.50 -0.75 * 178. OS: -4.25 -1.25 * 005. The optometrist suggested that I pick between 1.61 and 1.67, so I purchased 1.67 Zeiss AS DP lenses for 49 []21 glasses since I figured that the thinner the better... was this overkill? After I got home I'm reading through ABBE values and eye strain due to higher index lenses and I'm getting cold feet.Dec 7, 2018 · 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. 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.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. 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 benefits mentioned above. If you have a prescription that is +4.25/-6.75 or below, you’ll benefit from the thinness of a 1.61 high index lens. 1.74 Strong Index. 방문 중인 사이트에서 설명을 제공하지 않습니다.In your case though, I wouldn't recommend it. While I would also recommend 1.74 hi index for your Rx strength, having the ability to make adjustments and such needed is going to make a world of a difference for you. In your case, having your eyes centered on the lens is going to be more important than for someone with a …• 8 yr. ago. HereComesBadNews. Is it worth going from 1.61 high index to 1.67? I wear glasses exclusively, no contacts, and because I'm an English professor (and I read all …1 day ago · SPX | A complete S&P 500 Index index overview by MarketWatch. View stock ... Short sellers increase bets against high-flying tech stocks Mar. 25, 2024 at 2:05 p.m. ET by Joseph Adinolfi. U.S ...Jul 24, 2021 · MR is the brand name of optical lens raw materials produced by Mitsui Chemicals in Japan. MR series is available in three different refractive indices (1.60, 1.67, 1.74): MR-7, MR-8, MR-10, and MR-174. MR-7 and MR-10 have higher thermal deformation temperature and excellent dyeing, which are widely used in the field of sunglasses.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 …Nov 25, 2020 · A high-index lens may be recommended if your optical prescription is above 2.00 diopters. High-index lenses have a refractive index above 1.50— ranging from 1.53 to 1.74. The image below compares the lens thickness of a regular plastic lens (1.50) to the most commonly prescribed high-index lenses. Note: The higher the refractive index, the ... 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 benefits mentioned above. If you have a prescription that is +4.25/-6.75 or below, you’ll benefit from the thinness of a 1.61 high index lens. 1.74 Strong Index. Cons of 1.50 Lenses. Lower index of refraction: While the lower index of refraction in 1.50 lenses provides them with a wider field of vision, it also means that they are not as efficient in bending light. This can result in thicker lenses for individuals with higher prescriptions, leading to a less appealing aesthetic appearance. 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 ... Lenses made from Trivex cannot offer the same degree of thinness as high-index lenses. The thinness in high-index lenses reduces the “Coke bottle” appearance and is ideal for those needing high visual correction. High costs. Trivex outperforms many other lens material alternatives. However, it can come at a …Feb 22, 2023 · There are a number of different lens index lenses available, with some better suited to certain prescriptions than others. You’ll generally find lens index in the following sizes: 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. Feb 5, 2024 · People with higher-order refractive errors, typically +4.00 diopters or more, are ideal candidates for aspheric lenses. The difference between conventional and aspheric lenses is most noticeable for farsighted people. Aspheric lenses also work for people who struggle with: Nearsightedness (myopia) Astigmatism; Age-related … Sort by: InverseMeters. • 4 yr. ago. 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. Jun 30, 2021 · High index lenses have a refractive index of 1.53–1.74. Polycarbonate, which has a refractive index of 1.59, offers a mix of strength and thinness. Many companies offer polycarbonate lenses for ... Polycarbonate VS High Index Lenses. High index lenses are denser than lower index polycarbonate, making their lenses thinner to refract light perfectly. That means if a polycarbonate lens needs 2 millimeters of material to refract light, the high index may only need 1 millimeter. High index and polycarbonate lenses are great choices if you’re ... If you were to compare them to a pair of glasses with Trivex lenses of the same prescription, you’ll find that high-index lenses are always thinner and even lighter in higher prescriptions. Weight High index lenses are lighter. Trivex lenses have a lower refractive index of 1.53 as compared to high-index lenses having 1.67 to 1.74. Feb 20, 2024 · 1.67 index lenses are suitable for prescriptions under +5.00/-8.00 and astigmatism correction between -3.00 and -4.00. 1.74 index lenses are the thinnest high-index lenses. This lens is suitable for stronger prescriptions above +5.00/-8.00 and astigmatism correction between -4.00 and -6.00. 1.67 High index lenses are up to 30% thinner than 1.50 Standard index lenses. Stronger prescriptions: They are recommended for individuals with high myopia or hyperopia, …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 ...1.67 High index lenses are up to 30% thinner than 1.50 Standard index lenses. Stronger prescriptions: They are recommended for individuals with high myopia or hyperopia, … One of my eyes is worse than the other (-0.25 vs +2.00) and in that eye, you can tell looks slightly bigger and "buggier" through that lens and it makes me self-conscious. I currently have 1.61 high index lenses, and am wondering if moving up to 1.67 would have any noticable affect on my eye size? Negligible difference to the average person? How Much Do High Index Lenses Cost? · 1.60 High Index Lenses are on average 20% thinner than ordinary CR39 plastic. · 1.67 High Index Lenses are on average 35% ....ZEISS Single Vision AS 1.67 is an extremely thin single vision lens in the range of plastic lenses available from ZEISS. It is extremely light and a very special lens in many ways. In 1997 ZEISS was Europe’s first manufacturer to succeed in polymerizing a plastic lens with the super-high index 1.665 for batch production.What is the difference between a 1.74 high index lens and a 1.67 high index lens? That's what's discussed in this video. If you have any more questions or ar...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 ...The index of refraction of the coating material is 1.41 and the index of the glass is 1.66. What is the minimum thickness of coating which should be placed on a lens in order to minimize reflection of 636 nm light? The index of refraction of the coating material is 1.41 and the index of the glass is 1.66. There are 2 steps to solve this one.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. …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 benefits mentioned above. If you have a prescription that is +4.25/-6.75 or below, you’ll benefit from the thinness of a 1.61 high index lens. 1.74 Strong Index.Edit2, seems like trivex 1.53 is still clearer than the 1.57 zenni offers according to their Lens Index & Material Guide, but it still doesn’t tell me what the 1.57 is made of, they only specify trivex fo 1.53, CR39 for 1.5, polycarbonate for 1.59 and everything high index is “MR”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 …Polycarbonate 1.59 Lenses: The most impact-resistant lenses for eyeglasses. They are 22% thinner than standard lenses and are recommended for children and sports, as well as prescriptions of +/- 4.00. 1.6 Index Lenses: High index lenses up to 25% thinner than the standard lenses. Recommended for prescriptions of -4.00 to +3.00.1.67 High Index – finished AR coated 1.67 UVProtect DuraVision Platinum UV Aspheric 4 – 7 1.67 UVProtect DuraVision Blue Protect UV Aspheric 8 – 11 1.67 HMCx Aspheric 12 – 15 1.67 High Index – finished …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 ...Suitability for High Prescriptions. For those with higher prescriptions, 1.67 high-index lenses are often recommended due to their ability to bend light more efficiently, resulting in a thinner lens. Trivex, while not as thin, still offers a lightweight solution with added durability.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.May 23, 2023 ... High index lenses are 30% thinner than Standard index (1.50). Suitable Material: Polycarbonate 1.59 are impact resistant. Best for ages 18 and ... 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 benefits mentioned above. If you have a prescription that is +4.25/-6.75 or below, you’ll benefit from the thinness of a 1.61 high index lens. 1.74 Strong Index. 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.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 … 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 these. 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 correction1.61-1.67 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.방문 중인 사이트에서 설명을 제공하지 않습니다.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.
Buy High Index Lenses. Trivex has a low index of 1.53, similar to standard plastic. High index plastic’s index ranges from 1.67 to 1.74, making it considerably thinner and more lightweight than Trivex, especially in higher prescriptions. High index plastic has similar scratch resistance to Trivex. . T mark
July 6, 2021. 66.1K views. 5 shares. If you find yourself in the position to purchase a new pair of glasses, you may stumble across the phrase “lens index.” Lens index is a measurement on the lens thickness chart that … 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… 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. That is, the differences in lens thickness and weight are minimal. While high index lenses also tend to block UV better than CR-39, this isn’t their primary selling point.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...Measurements of lens flatness (base curve) on 1.60 ZEISS ClearView FSV lenses compared to ZEISS SPH FSV lenses over a range of prescriptions (-5D, -3D, -1D, +1D, +3D, +5D with and without cyl -2D). Maximum reduction of 49 % of -5.00D with and without cyl -2D. Quantitative analyses by Technology & Innovation, Carl Zeiss Vision GmbH, 2020.As for 1.67 high index lenses specifically, they are 20 percent thinner than polycarbonate lenses with the same prescription. With these basics in hand, we arrive at the main …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 .Hi,I’m just wondering – is there a difference between 1.61 versus 1.67 high index lenses if my script is -1.75 L and -1.5 R? menu Whirlpool Go to navigation. Whirlpool. Search. Forums. Lifestyle. Health. 1.61 versus 1.67 high index prescription lenses. Archive View Return to standard view.Feb 4, 2022 · Hi there! Thanks for checking out my video, I hope it helped. I've been glassy since I was young and so I know how important it is to choose high index glas...If you have a very strong prescription, you should consider ultra thin high index 1.74 lenses. High Index 1.74 lenses are the thinnest, flattest, and most cosmetically appealing lens ever developed. These ultra thin lenses are nearly 50% thinner than plastic and 5% thinner than 1.67 high index lenses, offering you the ultimate in technology and ...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 …Feb 4, 2022 ... Hi there! Thanks for checking out my video, I hope it helped. I've been glassy since I was young and so I know how important it is to choose ...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 …Feb 20, 2024 · HD lens technology offers the highest level of vision improvement available with glasses. They are available in high-index, photochromic, bifocal, or progressive lenses. These lenses are customized to create sharper images, brighter colors, and crisp focus. You’ll see things through HD lenses as if you were seeing them with natural vision. Starting with 1.61 vs 1.67 high index lenses — the 1.67 lens is extremely thin whereas despite still being stylish, the 1.61 lens is extra-thin. The 1.67 lens is a great choice for extra-strong prescriptions. 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 … 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 $40 more expensive. These are about 55mm wide lenses, is there a way to estimate how thick the lenses would be? Am I asking too much out of these frames for such a high prescription? .