Advantages of High-Index Lenses

Looking for new eyeglasses? In addition to choosing an attractive and comfortable pair of frames, make sure to consider the lens material too. 

Much like frames, eyeglass lenses come in a range of options with regard to design, material and coating. These factors typically have an impact on the comfort of the glasses and your vision, so don’t forget to also ask about these things when shopping for new specs at an eye clinic.

If you have a strong prescription, you might want to inquire about high-index lenses. To give you a better idea of how you can benefit from high-index lenses, Downtown Eyes shares more information below.

Essential Facts About High-Index Lenses

High-index lenses bend or refract light in a more efficient way than plastic lenses or regular glass. This is mainly due to their higher index of refraction, which also enables the lenses to be made thinner. High-index lenses are usually recommended to patients who have strong eyeglass prescriptions for nearsightedness, farsightedness or astigmatism.

If you have a prescription lower than +/- 2.00, you likely won’t see much difference between standard lenses and high-index lenses. Furthermore, the lenses typically used for such prescriptions aren’t thick or heavy, so the thinner high-index lenses won’t really offer any significant benefit. However, if your prescription is above +/- 2.00, the difference between high-index lenses and regular lenses would be dramatic. 

High-Index Lenses vs. Standard Lenses

The traditional plastic lenses used for stronger prescriptions are super thick and heavy. These can be quite uncomfortable for the wearer. So, if you want to have a more comfortable experience when wearing eyeglasses, you should consider high-index lenses. Standard lenses can also cause a “bug eye” look, which is eliminated with high-index lenses due to their aspheric design.

Despite being thinner, high-index lenses can still properly correct your vision. Their design enables light to refract more efficiently with less material. That’s why high-index lenses are thinner. 

How Thin Are High-Index Lenses?

High-index lenses can be made significantly thinner than standard lenses, but how thin depends on several factors including:

• Lens prescription

• Lens index

• Lens design

• Size and shape of the frame

Of course, you can’t do anything about your lens prescription. But when it comes to the other three variables, you can make certain choices that would allow you to have the thinnest lenses possible. If you’d prefer thinner lenses, these are some of the tips that your eye specialist will likely share with you:

• Ensure your lens material has a refractive index greater than 1.60. Generally, a higher index of refraction means thinner lenses. Lenses that have a refractive index of 1.67 and higher can be made with less than half the thickness of regular plastic lenses. Polycarbonate lenses with an index of 1.59 may only be 20% thinner than regular plastic lenses.

• Opt for high-index lenses with an aspheric design. Aspheric lenses have flatter curves, so they have a recognizably slimmer profile than regular plastic lenses.

• Stick to smaller frames. Smaller frames make use of thinner high-index lenses. So if thinness is a priority for you, make sure that your frames are also as thin as possible. Apart from that, your pupils should be close to the center of the lens opening in the frame. This will help further reduce lens thickness.

How Light Are High-Index Lenses?

Since high-index lenses are thinner, you might expect them to be much lighter than standard lenses. However, the weight of high-index lenses depends on how dense the material is. Some high-index lenses are thinner than other lenses due to their higher index of refraction, but they still may be heavier than thicker lenses. This usually happens when the lenses are made of a material with a higher density.

In conclusion, if it’s important for you to wear the lightest possible glasses, you should select a material with a high index of refraction and a low specific gravity. Some specific lenses that would be good options are the following:

• 1.67 high-index plastic lenses

• 1.71 high-index plastic lenses

• 1.74 high-index plastic lenses

The lenses listed above can be 25-30% lighter than regular plastic lenses, and they have less than half the weight of regular glasses. Since these lenses are quite specific, don’t hesitate to ask your optometrist for more information.

How Much Do High-Index Lenses Cost?

Typically, lenses with a higher index of refraction come with a higher price tag. In fact, it is common for 1.67 high-index lenses and 1.74 high-index lenses to cost three to four times more than standard plastic or glass lenses.

AR Coating

All lens materials are able to block some light from passing through the lens. This causes the light to be reflected back from the lens surface, creating distractions and reducing the clarity of night vision. Standard glass or plastic lenses typically reflect around 8% of light, which would otherwise reach the eye. Meanwhile, high-index lenses are capable of reflecting up to 50% more light than standard lenses.

Due to their higher reflectivity, high-index lenses should have an anti-reflective lens coating or AR coating. With this type of coating, high-index lenses can transmit up to 99.5% of light to the eye, ensuring optimum vision for the wearer.

It is also worth noting that AR coating practically eliminates lens reflections. This makes high-index lenses look almost invisible, so other people can see your eyes and not get distracted by the reflections in your lenses. R-coated high-index lenses can also help sharpen your night vision—a crucial advantage for people who frequently drive at night.

If you have more questions about high-index lenses, make sure to ask your optician before settling on a new pair of glasses. Remember all the essential considerations that you have to make when choosing eyeglasses that suit your style and ensure your comfort.

Schedule Your Appointment Today!

Downtown Eyes is a trusted establishment with years of experience providing quality eye care, products and services. Our expertise covers eye examinations, LASIK surgery co-management and treatment of common eye problems such as dry eye, red eye/pink eye and computer vision syndrome, as well as eye diseases like glaucoma, cataracts, diabetic eye disease, macular degeneration and more. We also offer a wide range of eyeglasses, sunglasses and contact lenses.

We ensure the comfort of each patient that requires our help. So whether you’re coming to our clinic for a contact eye exam or treatment of an eye disease, you can count on our staff to provide you with personalized, attentive care. Your satisfaction is very important to us at Downtown Eyes.

Call (612) 333-EYES (3937) (Minneapolis) or (612) 869-1333 (Richfield). You can also fill out our contact form to schedule an appointment.