How to Choose the Right Lens Thickness for Your Eyeglasses

Choosing new glasses, whether single-vision lenses or strong prescription glasses, can feel like a big decision. You want to see clearly, of course, but the way your glasses look matters, too. 

Lens thickness plays a big role in both. The right lens thickness can make your glasses look good on you.

Thicker lenses have some unsightly optical effects like power rings (rainbow like colored rings) around the edges of high minus powered glasses. Some frames, by their design require thinner lenses. If there is a narrow hinge, then a thicker edge will create a problem in closing the frame while storing it.  

 In this guide, we will discuss key factors that should guide your choice.

Understanding Lens Thickness

Several factors affect eyeglass lens thickness and weight. These include your prescription, pupillary distance and frame size. 

Lens material too plays a crucial role. The refractive index measures light bending. Lenses with a higher refractive index bend light more. Thus, thinner & the thinnest lenses for high prescriptions can be made with a higher refractive index, which will be lighter.

The denser the lens material, the more the refractive index. Thus, the lens material of thinner and lighter lenses is denser.

High Index Lens Benefits

Most people talk about thinner and higher index lenses specifically for myopic or minus powered spectacles. However, there is great merit in choosing high index in hyperoic or plus powered specs as well. 

• If you are hyperoic and have high plus power, then the cenrter of the lens will bulge out and lenses will be thicker towards the nose part of the frame. Opting for higher index lenses in plus power will make the edge towards the nose less prominent and will make the adjustment of nose pads in metal frames easier.

• If you opt for higher index lenses, the edge thickness & the effect of power rings is significantly reduced. The remainder of the power rings can be further addressed with anti-reflection treatment on high index lenses.

Factors to Consider for Lens Thickness Selection

Several factors determine eyeglass lens thickness & weight. These affect both your vision and your style.

1) Your Prescription Strength 

This is a big one. If your given prescription is strong, the lenses will likely be thicker. High prescriptions need more lens material and hence, thicker glasses. This achieves the needed vision correction.

2) The Eyeglass Frame Rim 

If your lenses are a bit thicker, a full-rim frame can help. Full rims conceal lens edge thickness. Rimless and semi-rimless frames suit thinner lenses, keeping the glasses looking sleek and light.

Plastic and thicker acetate rimmed frames will cover more thickness than metal rims.

3) Pupil Distance and Face Shape 

The distance between your pupils can affect lens thickness. Your face shape is another thing to consider. If your eyes are closer together, then you will most likely need higher-index lenses; otherwise, the lenses will end up thicker, especially in rectangular and oversized frames.

4) Your Lifestyle 

 Active people might want impact resistant lenses made of polycarbonate material. This is something to discuss with your optician.

5) Your Budget

What you want to spend can affect your lens choices. The cost of thin eyeglass lenses, made with high index materials, can be a bit higher than standard/conventional lenses. 

6) Aesthetics

Thinner lenses make the spectacles feel better and look more appealing. Some frames need thinner lenses because the design and the construction do not accommodate thicker lenses. 

7) Frame Shape

Oversized frames require higher index lenses, irrespective of the kind of power you have. 

• If you have minus power then the lens edge will be thicker. 

• And, if you have plus power, the lens surface will look overly bulging & the lens will be thicker at the nasal edge. 

• Similarly, a rectangular frame with higher index lenses should also be preferred.

8) Frame Style

Usually higher index lens materials like polycarbonate and CR 1.6 index are stronger than regular index (1.5) and mid-index (1.56) materials.  Hence, they are better suited for rimless frames, semi-rimed or semi-rimless also known as half-rimed or half-rimless, nylon fitting or supra frames.

R. Kumar Recommended Lens Materials 

Wondering how to get thinner eyeglass lenses? If you are looking to reducing eyeglass lens thickness, get your new glasses in the appropriate lens material.

Different materials have a huge impact on how thick your glasses feel and look. These materials each have their own features and can affect the lens thickness for most prescriptions.

1) Plastic Lenses

There are a variety of plastic materials available in an array of indices.  The primary ones are CR39, Polycarbonate and Trivex. Plastic lenses are lighter and don’t shatter upon breakage or in case of accidents. Hence, they are more comfortable for long hours of use.  They are also safer to use. 

Better materials like high index plastic, polycarbonate and trivex offer higher impact resistance than normal or low index plastics.

A. CR39 

It is the most versatile material with various index options like 1.49 or 1.5, 1.56, 1.6, 1.67 and 1.74. 

• CR39 offers exceptional visual clarity, which can be enhanced by coupling with advanced anti-reflection treatments.  

• It can be tinted to make polarized or numbered sunglasses.  

• It is available in regular, polarised, and transitions or react to light (change color in the sun) options. 

i. Low index and mid-index: These are CR1.5 (low) and CR1.56 (mid) materials. These are usually thicker and softer materials. They should not be opted if your power is more than +3/-3. 
They are a strict no-no for rimless and semi /half rimless frames.

ii. High index: CR1.6 and CR 1.67 lenses are thinner than conventional plastic and regular glass lenses. They are relatively stronger and suitable for rimless and half /semi rimless frames.  

iii. Super-high or Ultra-high Index: CR 1.74 is the thinnest available lens material at the moment which offers the finest aesthetics.

B. Polycarbonate

It comes in 1.59 index, which is more or less similar in thickness to CR1.6 index and is more impact resistant than CR39.  It is a material of choice for sports and active lifestyles.

C. Trivex

It is one of the most impact-resistant materials, but its index is relatively low. Hence, it is thicker and less preferred. However, if you have a low prescription, it offers great optical clarity with the strongest lens material available at the moment.

2) Glass Lenses

Glass or mineral lenses have been the mainstay of powered spectacles for as long as we can remember.  However, over the past couple of decades, due to rapid development in plastic lens materials and advanced treatments on plastic lenses, glass has become the lesser preferred material for spectacles. 

Glass certainly provides great optical clarity and is resistant to scratching. It is available in various indices like 1.523, 1.61, 1.7, 1.8 and 1.9.

Since they are brittle and heavy, glass lenses are risky, especially for children and for people with active lifestyles. Moreover, glass is heavy and hence, not comfortable for long hours of continuous use. 

R. Kumar Recommended Lens Thickness for Different Prescription Ranges 

Lens thickness choice depends on your prescription. Here are tips from R Kumar, our expert. Follow these for great vision and comfortable glasses.

A. Mild to Moderate Prescriptions (up to +/- 2.00 diopters)

 Got a mild to moderate prescription? That means you have some good options for your lenses. Standard plastic (CR 39) lenses work well. Polycarbonate lenses are also a great choice. A refractive index of 1.5 is generally recommended. These will give you clear vision. They can also be made relatively thin for a nice appearance.

B. Moderate to Strong Prescriptions (+/- 2 to +/- 6 diopters)

For this range, there are many high-index lens benefits. Look for a lens index between 1.56 and 1.59. Lenses with this index are designed to be thinner. This makes your glasses more comfortable. It also improves how they look. You'll notice a real difference in thickness compared to standard plastic. 

Do consider CR1.67 if you are choosing an oversized frame or if your pupils are close-set.

C. Strong Prescriptions (+/- 5.25 diopters or higher)

The thinnest eyeglass lenses are usually best for this range. We suggest high index lenses. Look for an index between 1.61 and 1.74. These materials reduce lens thickness the most. This results in lighter eyeglasses. They will also look much more attractive.

Choosing eyeglass lenses and their thickness involves more than just your prescription. Think about your frames. Consider your face shape. And let your personal style guide you. Your comfort and clear vision are key. Our team, with the expertise of R Kumar, is here to help you find the perfect combination.

FAQs 

1. Will thicker lenses affect the clarity of my vision?

Ans. The thickness of your lenses is separate from how clear your vision will be. The lens material and its optical quality determine your visual acuity. Thicker lenses can provide the same clear vision as thinner lenses. 

We at R Kumar, prioritize quality in all our lenses, regardless of lens and edge thickness. 

2. Will high-index lenses make my glasses more expensive?

Ans. Yes, they usually have a higher price than standard lenses. They come with an extra cost, but it's not a fixed amount. The cost depends on the specific high index you need. We believe in transparent pricing. Our team will discuss all options with you to find the best value for your vision and your budget.

3. Are high-index lenses suitable for all prescriptions?

Ans. Generally yes, though not necessarily. High-index lenses are fantastic for making strong (or most) prescriptions thinner. If your prescription is moderate to strong, they are often ideal. But for mild prescriptions, you might not need them. Other materials like standard plastic or polycarbonate can offer good vision and comfortable thickness. 

4. Can I still achieve a fashionable look with thicker lenses?

Ans. Yes! Style is all about expressing yourself. Lenses with thick edges can be a bold and distinctive part of your look. Many stylish frames are designed to complement thicker lenses. Think bold acetate frames or retro-inspired frame and lens designs.