What Are High-Index Lenses?

If you're tired of wearing thick, heavy glasses due to a strong prescription, high-index glasses might be the solution you've been searching for. These innovative lenses offer a thinner, lighter alternative without compromising visual clarity.

In this article, we'll discuss their benefits, drawbacks, and various types to help you determine if they're the right choice for your vision needs.

What Are High-Index Glasses?

High-index glasses have a higher refractive index and bend light more efficiently, making them ideal for correcting strong prescriptions. They’re also made of a special plastic material, making their lenses thinner and lighter.

The higher your prescription, the higher the index you need. For reference, standard plastic lenses have a refractive index of 1.50. On the other hand, high-index lenses can have a refractive index of 1.53 to 1.74.

If you have a strong prescription, a lens with a high index of 1.74 could be up to 50% thinner than a standard lens with the same prescription strength. Overall, high-index glasses can be a great alternative to bulky and heavy lenses used for higher prescriptions.

What Vision Problems Do High-Index Lenses Correct?

High-index plastic lenses correct all types of refractive errors, including:

• Myopia (nearsightedness)
• Hyperopia (farsightedness)
• Astigmatism
• Presbyopia (age-related farsightedness)

What Are the Pros & Cons of High-Index Glasses?

CR-39 plastic is typically the standard for most people with high prescriptions. They’re inexpensive and have excellent optical quality. 

However, high-index glasses are lighter, slimmer, and more comfortable than traditional lenses. The reduced weight can also alleviate pressure on your nose and ears.

However, high-index glasses can come with a few drawbacks. We created a table to clearly illustrate the pros and cons of high-index glasses:

Pros	Cons
Improved vision correction.	More expensive than traditional glasses.
Built-in UV protection.	Less impact-resistant compared to polycarbonate or Trivex lenses.
Better cosmetic appeal and access to different frame styles.	Prone to scratches.
Good peripheral vision with an aspheric design.	Reflects up to 50% more light than regular plastic lenses.
Makes your eyes look more natural, preventing “bug eyes”.

Types of High-Index Glasses

There are three different high-index lenses and each one differs in thickness and is used for different prescriptions:

• 1.61. Suitable for prescriptions around +3.00/-6.00 or less and astigmatism correction of -3.00 or less
• 1.67. Suitable for prescriptions under +5.00/-8.00 and astigmatism correction between -3.00 and -4.00
• 1.74. The thinnest high-index lenses and are good for stronger prescriptions above +5.00/-8.00 and astigmatism correction between -4.00 and -6.00

These lenses can be combined with other features and lens types to suit different needs:

• Aspheric lenses. Slimmer and help to minimize the edge thickness, particularly on high myopic prescriptions. 
• Photochromic lenses. Clear indoors and turn dark when outside to block 100% of UV rays and reduce glare.
• Polarized lenses. Reduce glare off horizontal surfaces, such as road surfaces and water.
• Bifocal lenses. Suitable for those who are presbyopic and need reading correction.
• Progressive glasses. Provide distance, intermediate, and near correction.
• High-definition lenses. Also known as digital lenses. These are highly customized lenses that deliver higher-quality vision than traditional lenses.

How Much Do High-Index Glasses Cost?

Depending on your choices, a pair of high-index lenses will cost between $100 and $300. Here’s what you can expect to pay depending on your choices:

• A single vision lens with a 1.67 or 1.70 index can cost around $100 to $150.
• Progressive bifocal lenses with a 1.67 or 1.70 index can cost between $150 and $200.
• Plastic lenses with a 1.74 index can cost between $175 to $225.
• Glass lenses with a 1.74 index can cost up to $300.

These prices increase depending on higher indexes, extras, and coatings. Tinted, transition, or polarized high-index lenses can also increase the price.

By understanding the different types, considering the pros and cons, and factoring in the cost, you can make an informed decision about whether high-index glasses are the perfect fit for your lifestyle and vision correction needs.