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Lens Thickness Comparison: Standard vs High Index vs Ultra Thin
Choosing the right lens material can dramatically change how your glasses look, feel, and perform. This lens thickness comparison highlights the real differences between standard plastic lenses (CR-39), polycarbonate lenses, 1.60 high-index lenses, and 1.67 ultra-thin lenses across common prescriptions like -2.00, -4.00, and -6.00. You’ll see how polycarbonate offers a thinner, impact-resistant alternative to standard plastic, while high-index materials like 1.60 and 1.67 provide even slimmer profiles for stronger prescriptions. If you’re wondering whether polycarbonate or high-index lenses are worth it for your prescription, this guide will help you make a confident, informed decision.
Ready for thinner, lighter lenses? Order new prescription lenses for your frames with free shipping both ways. Choose single vision lenses or progressive lenses .
What Determines Lens Thickness?
Lens thickness depends on four main factors:
- Your prescription strength
- Lens material (standard vs high index)
- Frame size
- Frame shape
Stronger prescriptions bend light more aggressively, which increases edge thickness - especially for minus (-) prescriptions. That is why thin lenses for stronger prescriptions are often recommended.
Lens Thickness Chart by Prescription Strength
Use this lens thickness chart as a simple starting guide. Exact finished lens thickness can vary based on your complete prescription, frame size, frame shape, pupillary distance (PD), cylinder and axis, and how your eyes are positioned inside the frame.
Lens Thickness Chart: Which Index Fits Your Prescription?
| Prescription Range | Typical Starting Choice | Thickness Goal | What to Know |
|---|---|---|---|
| Up to ±2.00 | Standard Plastic 1.50 or Polycarbonate 1.59 | Standard / relatively thin | Often suitable for lower prescriptions. A smaller frame can help keep lenses looking thinner. |
| ±2.00 to ±4.00 | Polycarbonate 1.59 or High Index 1.60 | Thinner profile | 1.60 is often chosen when a slimmer cosmetic appearance is important. |
| ±4.00 to ±6.00 | High Index 1.60 or 1.67 | Thin to ultra-thin | Higher-index materials become more useful as prescription strength and visible edge thickness increase. |
| Above ±6.00 | High Index 1.67 or 1.74 | Maximum practical thickness reduction | Frame size and shape matter greatly. 1.74 may be considered when minimizing thickness is a priority. |
Important: This lens thickness chart is a general guide, not an exact thickness calculator. Two people with the same sphere power can receive different finished lens thicknesses because the frame, PD, cylinder, axis, lens design and required minimum thickness can all affect the result.
Lens Material & Thickness Comparison
| Lens Material | Relative Thickness | Weight / Feel | Durability | Best Suited For | Main Difference |
|---|---|---|---|---|---|
| 1.50 Standard Plastic | Thickest of these options | Standard feel | Everyday use | Lower prescriptions | Budget-friendly traditional lens material. |
| 1.59 Polycarbonate | Thinner than standard plastic | Lightweight | Highly impact resistant | Everyday wear, active use, many rimless applications | Good balance of durability, weight and thickness. |
| 1.60 High Index | Thin | Slimmer feel | Everyday prescription use | Moderate prescriptions | A common upgrade when you want noticeably thinner lenses. |
| 1.67 High Index | Ultra-thin | Reduced bulk for stronger prescriptions | Everyday prescription use | Moderate to strong prescriptions | Greater cosmetic thickness reduction than 1.60. |
| 1.74 High Index | Thinnest commonly available plastic option | Designed to reduce visible lens bulk | Everyday prescription use when appropriate | Higher prescriptions | Used when maximum practical thickness reduction is the main goal. |
What Else Affects Eyeglass Lens Thickness?
Lens index is only part of the answer. Stronger prescriptions usually create more thickness, but the frame can make a major difference too. Large or wide frames generally require more lens material, while smaller and rounder frames can often reduce visible thickness. Pupillary distance (PD), cylinder and axis can also change where the thickest part of the lens appears.
Minus (-) prescriptions are generally thinner in the center and thicker toward the edges. Plus (+) prescriptions are generally thicker through the center and thinner toward the edges. For the best cosmetic result, choose the lens index and frame together rather than looking at prescription strength alone.
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Choose the lens type you need, send us your frames, and we will install your new prescription lenses.
Quick Thickness Takeaway
Higher-index lenses can reduce visible thickness, but the best result comes from matching the lens material to both your prescription and your frame. If you are unsure, use the lens thickness chart above as a starting point and consider frame size before choosing the highest index.
Shop Prescription Lenses for Your Frames
Start with your vision type. You can upload your prescription during checkout or send it later.
Frequently Asked Questions
Are high index lenses stronger?
No. They simply use a denser material that bends light more efficiently.
Do thinner lenses affect clarity?
No. Optical clarity remains excellent when properly manufactured.
Is polycarbonate stronger than other materials?
Polycarbonate is highly impact resistant, making it ideal for active lifestyles, kids, and rimless frames.
Do I need high index for −2.00?
Not necessarily — unless you prefer a thinner cosmetic profile.
Final Tip Before You Order
If you are unsure which lens index to choose, start with your prescription strength and frame size. Stronger prescriptions and larger frames benefit the most from high index materials. Choosing the right lens material improves comfort, appearance, and long-term satisfaction.
Why Choose RenewLens?
Prescription lenses professionally installed in your frames.
Precision fitting and careful quality inspection.
Prepaid shipping to RenewLens and back to you.
Covered by our 60-day quality guarantee.
Don’t settle for thick, heavy lenses. Upgrade your vision and comfort.
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Select single vision or progressive lenses and use code RENEW15 for 15% off your first order.