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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.
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.
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.
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 lenses||High index lenses|
|thicker lens material||thinner lens material|
|standard light-bending capabilities||more efficient light-bending capabilities|
|more durable||more fragile|
|fewer frame options||more frame options|
|more affordable||more costly|
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.
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.
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.
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.
The following are some online retailers offering high index lens options.
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 promotions
- several lens and frame customization options
- direct billing with some health insurance providers
- a prescription scanner for matching a person’s current glasses
- a 14-day return period
- free standard shipping
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 prescriptions
- the ability to choose transitions lenses or sunglasses for any frame or lens
- a selection of brand-name frames
- frequent sales
- acceptance of health savings accounts (HSAs) and flexible spending accounts (FSAs)
- the opportunity to try glasses virtually
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 coatings
- online eye exam for those who need to update their prescription
- free standard shipping
- replacement items if necessary due to manufacturing errors
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 cost
- frames featuring themes from child-friendly popular culture
- a 30-day returns policy
- free standard shipping
Pair Eyewear also accepts HSA and FSA payments.
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 frames
- adult’s and children’s styles
- the ability to make any frame into sunglasses
- shipping that starts at $5
- a 30-day returns policy
- use of FSA and HSA accounts
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
- wash the hands before handling their contact lenses
- store the contact lenses in a clean container with fresh solution
- clean and replace contact lenses regularly
- keep to all scheduled checkups with an eye doctor
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
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.
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.