A guide to high index lenses: Benefits and more Health ConditionsHealth ConditionsAlzheimer's & DementiaAnxietyArthritisAsthma & AllergiesBreast CancerCancerCardiovascular HealthCOVID-19Dermatology & SkincareDiabetesEnvironment & SustainabilityExercise & FitnessEye HealthHeadache & MigraineHealth EquityHIV & AIDSHuman BiologyInflammatory Bowel DiseaseLeukemiaLGBTQIA+Men's HealthMental HealthMultiple Sclerosis (MS)NutritionParkinson's DiseasePsoriasisSexual HealthWomen's HealthDiscoverNewsLatest NewsOriginal SeriesMedical MythsHonest NutritionThrough My EyesNew Normal HealthPodcastsHow to understand chronic painWhat is behind vaccine hesitancy?The amazing story of hepatitis C, from discovery to cureNew directions in dementia researchCan psychedelics rewire a depressed, anxious brain?Why climate change matters for human healthToolsGeneral HealthDrugs A-ZHealth HubsHealth ToolsBMI Calculators and ChartsBlood Pressure Chart: Ranges and GuideBreast Cancer: Self-Examination GuideSleep CalculatorHealth ProductsAffordable Therapy OptionsBlood Pressure MonitorsDiabetic SuppliesFitness TrackersHome GymsGreen Cleaning ProductsHow to Shop for CBDQuizzesRA Myths vs FactsType 2 Diabetes: Managing Blood SugarAnkylosing Spondylitis Pain: Fact or FictionConnectAbout Medical News TodayWho We AreOur Editorial ProcessContent IntegrityConscious LanguageNewslettersSign UpFollow UsMedical News TodayHealth ConditionsDiscoverToolsConnectSubscribe A guide to high index glasses Benefits where to get them and moreMedically reviewed by Jenna Stoddard, OD — By Jenna Fletcher — Updated on May 17, 2022We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process. High index lenses are glasses lenses that are thinner and lighter than standard options. They may benefit people with stronger prescriptions who might otherwise have heavier, thicker lenses. Share on PinterestAn estimated 150 million people in the United States have a refractive error. The four most common types of refractive error are astigmatism, nearsightedness, farsightedness, and age-related farsightedness. People with refractive errors often require stronger prescriptions. They may therefore benefit from using high index lenses. In this article, learn more about high index lenses, what to consider when choosing them, and where to purchase them. Understanding an optical prescription Glasses and contact lens prescriptions contain different numbers and abbreviations. When looking at a prescription, a person will likely notice the following information:OD: This stands for oculus dexter and refers to the right eye.OS: This stands for oculus sinister and refers to the left eye.OU: This stands for oculus uterque and refers to both eyes. Displayed after each of these letters will be a numerical value with either a plus (+) or minus (-) sign. The higher the number, the more correction a person’s eye needs. The plus sign indicates that a person has farsightedness, and the minus sign indicates that a person has nearsightedness. CYL and axis If a person’s eye has an unusual curve, values are added for cylinder (CYL) and axis. The eye is usually spherical, but a new curve can develop and change the eye shape. The CYL indicates how much curve is present. The axis indicates where the curve appears on the eye. A person may need similar corrections in both eyes or different corrections in each eye. About high index lenses High index lenses are made using a type of plastic that bends light more efficiently than other common types of lenses. The result is a lighter, thinner lens that more easily fits inside regular frames. If a person’s eyesight prescription shows a higher number after the plus or minus sign, they have what experts call a strong prescription, which typically also means that they have thicker, heavier glasses lenses that need a more durable frame. This can restrict a person’s choice when looking to purchase new glasses. High index corrective lenses bend light more efficiently than standard lenses, allowing for a thinner, lighter lens option. This makes it easier to fit them inside regular frames and opens up a wider selection of glasses. Those with a weaker prescription can also purchase high index lenses, as they are often lighter than traditional lenses. High index vs regular lenses The table below shows a comparison between standard lenses and high index lenses.Regular lensesHigh index lensesthicker lens materialthinner lens materialheavierlighterstandard light-bending capabilitiesmore efficient light-bending capabilitiesmore durablemore fragilefewer frame optionsmore frame optionsmore affordablemore costly Benefits of high index lenses Potential advantages of high index glasses include the following:There are more frame options to choose from. For instance, it is possible to choose transitions lenses.High index lenses are lighter than regular lenses, which may ease any discomfort around the temples and the bridge of the nose.High index lenses are thinner than regular ones, which may help avoid making eyes look smaller when wearing glasses. Disadvantages of high index lenses The following are some disadvantages of high index glasses:High index lenses are more brittle than regular ones.They tend to cost more than regular lenses.High index lenses tend to be less scratch-resistant than regular ones. Types of high index lenses All glasses lenses work by bending light, and how quickly the light travels through the lens is known as the refractive index. The refractive index generally defines the type of high index lens a person has. Plastic lenses, known as CR-39, have a refractive index of 1.5. 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 an additional fee. Lenses that are 1.74 are the thinnest lenses a person can purchase. Typically, only people with very high prescriptions use these. They are often the most expensive option. What to consider when choosing Not everyone needs high index lenses, and some online retailers discourage people with prescriptions of less than +/-6.00 from purchasing lenses that are 1.74. Some factors that a person may like to consider before purchasing expensive high index upgrades include:Aesthetics: A thinner lens can help reduce the magnifying effect of a person’s eyes, leading to a more natural look.Cost: High index lenses are often an added feature at many online and traditional retailers.Weight: Wearing regular lenses with stronger prescriptions may become uncomfortable due to their size and weight. Where to buy The following are some online retailers offering high index lens options. GlassesUSA GlassesUSA offers several different frame and color options, including ones from brand-name designers. In addition to glasses, it can also fulfill contact lens prescriptions. Its thinnest lens goes up to 1.67. Other features and services include:frequent sales and promotionsseveral lens and frame customization optionsdirect billing with some health insurance providersa prescription scanner for matching a person’s current glassesa 14-day return periodfree standard shippingSHOP NOW EyeBuyDirect EyeBuyDirect offers a large selection of frames to accommodate prescription and nonprescription lenses. A person can choose their frames, color, and any added features for their lenses. Some other features include:high index lenses for stronger prescriptionsthe ability to choose transitions lenses or sunglasses for any frame or lensa selection of brand-name framesfrequent salesacceptance of health savings accounts (HSAs) and flexible spending accounts (FSAs)the opportunity to try glasses virtuallySHOP NOW Lensabl Lensabl offers several brand-name frames and styles of eyewear. In addition, it offers 1.67 and 1.74 high index options for prescriptions over +/-4.00. Some other services include:multiple lens coatingsonline eye exam for those who need to update their prescriptionfree standard shippingreplacement items if necessary due to manufacturing errorsSHOP NOW Pair Eyewear Pair Eyewear is a boutique glasses shop that primarily caters to children. The majority of its lenses are polycarbonate with added scratch-resistant, UV, and antireflective coatings at no extra charge. The company also offers:lenses from -9.00 through +6.00, plus higher prescriptions for an added costframes featuring themes from child-friendly popular culturea 30-day returns policyfree standard shipping Pair Eyewear also accepts HSA and FSA payments.SHOP NOW Payne Glasses Payne Glasses can accommodate high index lenses up to 1.74. It offers a variety of different style frames and colors. Each of its lens options can also include extras such as transitions, which react to different lighting levels, and coatings, which help protect the lenses. Some additional features and services include:prices starting below $10 on several framesadult’s and children’s stylesthe ability to make any frame into sunglassesshipping that starts at $5a 30-day returns policyuse of FSA and HSA accountsSHOP NOW Can people with strong prescriptions use contact lenses Like glasses, contact lenses can accommodate higher prescriptions. The American Optometric Association says that a person may prefer contact lenses for the following reasons:They provide better and more natural eyesight.They are more convenient during physical activities and sports.They do not fog.They offer a more natural field of vision. However, when using contact lenses, there are safety considerations to make. To protect the contact lenses and one’s eyesight, the Centers for Disease Control and Prevention (CDC) recommend that a person:wash the hands before handling their contact lensesstore the contact lenses in a clean container with fresh solutionclean and replace contact lenses regularlykeep to all scheduled checkups with an eye doctor Frequently asked questions Below, we answer some commonly asked questions about high index lenses. Do I need high index lenses Generally, people with stronger prescriptions may benefit more from high index lenses. High index lenses are thinner than regular lenses, which may decrease the weight of the glasses and avoid making eyes look smaller. A person should always discuss which lenses are most suitable with an optician. Why are high index lenses more expensive High index lenses cost more than regular lenses due to the materials they contain. Manufacturers usually make high index lenses from polyurethane resin, which costs more to produce than regular lenses. What is the proper weight for high index lenses There is no standard weight for high index lenses. Different manufacturers may offer different weights. The prescription strength of the glasses may also affect the weight. Do high index lenses offer UV protection Eyeglass companies state that most high index lenses offer nearly 100% UV protection. However, people should discuss whether they will need to purchase UV coatings for their lenses with an optician. Will high index lenses make my eyes look smaller High index lenses are thinner than regular lenses, so they should not make a person’s eyes look smaller. Summary High index lenses are lighter and thinner than traditional lenses. They can be a good choice for people with stronger glasses prescriptions. Some disadvantages include added costs. A person with a lower prescription may find that polycarbonate lenses offer a sturdy, thinner option that is better for those who are very physically active. Last medically reviewed on June 29, 2021Uncategorized 10 sourcescollapsedMedical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.Armenta, A. (2022). Lens index meanings.https://www.visioncenter.org/resources/lens-index/Comprehensive eye exams. (n.d.).https://www.aoa.org/healthy-eyes/caring-for-your-eyes/eye-exams?sso=yHealth savings account (HSA). (n.d.).https://www.healthcare.gov/glossary/health-savings-account-hsa/Pillay, R., et al. (2020). Historical development, applications and advances in materials used in spectacle lenses and contact lenses.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7532918/Porter, D. (2020). How to read an eyeglasses prescription.https://www.aao.org/eye-health/glasses-contacts/how-to-read-eyeglasses-prescriptionProtect your eyes. (2021).https://www.cdc.gov/contactlenses/protect-your-eyes.htmlRefractive errors. (2022).https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/refractive-errorsTypes of contact lenses. (n.d.).https://www.aoa.org/healthy-eyes/vision-and-vision-correction/types-of-contact-lenses?sso=yUsing a flexible spending account (FSA). (n.d.).https://www.healthcare.gov/have-job-based-coverage/flexible-spending-accounts/Vicchrilli, S. J. (2011). Ophthalmic abbreviations 101.https://www.aao.org/young-ophthalmologists/yo-info/article/ophthalmic-abbreviations-101FEEDBACK:Medically reviewed by Jenna Stoddard, OD — By Jenna Fletcher — Updated on May 17, 2022 Latest newsWhat sets 'SuperAgers' apart? Their unusually large neuronsOmega-3 may provide a brain boost for people in midlifeSeasonal affective disorder (SAD): How to beat it this fall and winterCDC: Monkeypox in the US 'unlikely to be eliminated in the near future'Why are more women prone to Alzheimer's? New clues arise Related CoverageGlassesUSA review: What to knowMedically reviewed by Vicente Diaz, MD, MBA GlassesUSA are an online company offering glasses, sunglasses, and contact lenses. Find out more about the brand, reviews, and eye care here.READ MORELensabl: Reviews and what they offerMedically reviewed by Angelica Balingit, MD Lensabl offer a range of eyewear products and services for purchase online, including contact lenses, glasses, and lens replacements. Learn more about…READ MOREPayne Glasses review Payne Glasses offers many glasses frame and lens options online. Learn about the company and tips for glasses shopping and eye care here.READ MOREEyeBuyDirect: Reviews, services, and moreMedically reviewed by Vicente Diaz, MD, MBA EyeBuyDirect offer a range of glasses and sunglasses for purchase online. They also offer prescription and blue light lenses. Learn about EyeBuyDirect…READ MOREHow to find out your glasses prescription A person can get their glasses prescription from their doctor's office. It is also possible to use an online service, but these are not suitable for…READ MORE