The Different Types of Eyeglass Lens Materials

The material from which a lens is made has little impact on the corrective power of the lens, but it can have a major impact on lifestyle. Learn about the different lens material options and make the best choice for your next pair of eyeglasses.

Optician helping customer to choose new spectacles
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Hi-Index Lenses

Hi-index lenses are made of a special plastic material that refracts light in a different way than regular plastic lenses. With hi-index lenses, vision can be corrected with less material, making the lens much thinner. Plastics are graded in numbers, such as 1.50 or 1.67. The higher the number, the thinner the lens. Because they are thinner, hi-index lenses are also lighter, making them more comfortable to wear. This is important to patients with high prescriptions, as their glasses can be made more cosmetically attractive and appealing. Hi-index lens materials tend to cost more than standard plastic lenses.

Polycarbonate Lenses

Polycarbonate lenses are made of a type of plastic that is more impact-resistant than standard plastic lenses. Polycarbonate lenses are also much thinner tvand lighter in weight. They are considered a high index plastic. Polycarbonate lenses also have built-in ultraviolet protection. Because of these properties, it is the lens material of choice for children’s lenses, sports lenses, and safety lenses.

However, some people with higher powers and high astigmatism often complain of poorer quality of vision, distortion, or sometimes a halo or color-ring effect in their peripheral vision with polycarbonate because it has a low abbe value. Abbe value is the amount of chromatic aberrations in a lens—the higher the number, the better the quality of vision through the lens.

Trivex Lenses

Trivex is a relatively new material that is similar to polycarbonate lenses but with higher quality optics, and thus provides a clearer vision. Trivex is lighter in weight than standard plastic but not quite as thin as polycarbonate. Trivex is a more rigid material, making it a better selection for rimless or drill mount frames, and is just as impact resistant as polycarbonate.

Aspheric Lenses

An aspheric lens design gives several advantages to eyeglass lenses. An aspheric lens has flatter peripheral curvatures than a regular spherical lens. This reduces the amount a lens may bulge out of an eyeglass frame, reducing magnification of the eyes, which improves cosmetic appearance. Flatter peripheral curves also reduce distortions that occur when looking away from the center of the lens, making vision much crisper. Aspheric lenses are also much lighter in weight than standard spherical lenses.

Anti-Reflective Coatings

An anti-reflective coating is applied to eyeglass lenses to reduce the amount of internal and external reflections on a lens. This increases the amount of light transmitted through the lens, which improves the quality of vision. The anti-reflective coating also decreases unwanted glare and halos at nighttime. It also makes the lenses appear somewhat invisible and very thin. While everyone could benefit from an anti-reflective coating, it is especially beneficial for people with high prescriptions, people who have a decrease in the vision at night, and professions in which cosmetic appearance is important.

Scratch-Resistant Coatings

Scratch-resistant coatings are applied to the front and back of lenses in the manufacturing process. Although it is important to realize that no lens is scratch-proof, this special coating does make lenses harder to scratch when dropped or rubbed against a hard surface. While most lenses are made with scratch-resistant coating, sometimes the term scratch-resistant coating indicates a type of “scratch warranty.” These warranties guarantee against scratches, ensuring the lenses will be remade if a scratch does occur. Be sure to clarify any warranty of this nature.

Ultraviolet Treatments

Ultraviolet treatment is applied to lenses to protect against harmful UV sun rays that can accelerate the development of cataracts and macular degeneration. It is extremely important to protect eyes from the damaging effects of the sun. UV treatment is easy to apply to lenses and is often included with the purchase of eyeglasses.

Polarized Lenses

Polarized lenses are usually used to make sunglasses. They are available most commonly in grey or brown tint but many other colors are available. Vertically polarized lenses decrease bright glare and reflections by blocking horizontal polarized reflected light. Polarized lenses have been used by fishermen for years to better deal with a bright light being reflected off the water and to see deeper into the water.

Photochromatic Lenses

Photochromatic lenses have a special chemical coating that makes them change to a dark tint in the sunlight and turn clear indoors. Photochromatic lenses are great for people who do not wish to carry a separate pair of prescription sunglasses.

It is important to note that photochromatic lenses will not change behind the windshield of a car—the windshield prevents most of the UV light from reaching the lens. However, there are some new lenses on the market that claim that they will change slightly inside a car. It's important to speak to your optician or optometrist about these options and try a sample, as it may not get dark enough for you.

A Word From Verywell

If you haven't been to the eye doctor in a while, you may be surprised at the number of options now available to make your eyeglass lenses work best for you. Your personal needs will help determine which lens materials and coatings would benefit your lifestyle the most. 

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  1. Roberts JE. Ultraviolet radiation as a risk factor for cataract and macular degeneration. Eye Contact Lens. 2011;37(4):246-9. doi:10.1097/ICL.0b013e31821cbcc9