Lens Thickness
Comparison Chart
How much thinner are high-index lenses?
Compare standard plastic, polycarbonate, 1.60, 1.67 and 1.74 lenses. Understand thickness by prescription, lens index and frame size before you buy.
Quick Answer
Which Eyeglass Lenses Are the Thinnest?
For comparable prescriptions and frame dimensions, high-index 1.74 plastic lenses generally offer greater thickness reduction than 1.67, 1.60 and standard 1.50 plastic. However, the best material depends on the prescription, frame, optical design, safety requirements and budget.
What Higher Index Means
The refractive index describes how strongly a lens material bends light. A higher index can deliver the required optical power using less lens curvature.
This can mean a slimmer center or edge profile, but it does not guarantee a specific finished thickness.
What Index Cannot Tell You
- The exact number of millimeters
- How much the finished lens will weigh
- Whether your frame is suitable
- The best optical trade-off for your needs
Material Comparison Table
Eyeglass Lens Thickness Comparison: 1.50 to 1.74
Compare the most common prescription lens materials by their potential to reduce thickness. These are general material characteristics, not fixed thickness promises.
| Lens Index | Material | Thickness Profile | Key Consideration |
|---|---|---|---|
| 1.50 | CR-39 standard plastic | Baseline | Good optical clarity and value for many lower prescriptions |
| 1.59 | Polycarbonate | Thinner potential than 1.50 | Lightweight, impact-resistant material |
| 1.60 | High-index plastic | Moderately thinner potential | Often considered for moderate prescriptions |
| 1.67 | High-index plastic | Greater thickness reduction potential | Often useful with stronger prescriptions |
| 1.74 | Ultra-high-index plastic | Among the thinnest common plastic materials | Premium cost and material/design limitations |
No. Some prescriptions gain only a modest cosmetic improvement from moving from 1.67 to 1.74. Higher-index materials can also involve differences in chromatic dispersion, weight, price and coatings.
Visual Lens Thickness Chart
Lens Thickness Chart: 1.50 vs 1.60 vs 1.67 vs 1.74
This illustrative example compares approximate lens edge thickness for a −5.00 D single-vision prescription in a 50 mm frame. It demonstrates how the finished edge may become slimmer as the lens index increases.
Illustrative Edge Thickness Comparison
Important: These are illustrative, approximate measurements from a published third-party comparison, not measurements from CV Optical's laboratory and not a quote for your glasses.
Source: Published Lens Thickness Examples ↗
Your finished lens may differ substantially because of cylinder, axis, PD, decentration, frame shape, minimum thickness and lens design.
Higher-index materials can offer visibly slimmer lens edges in strong minus prescriptions. The exact benefit should be calculated for your actual frame.
Thickness by Prescription
Lens Thickness Comparison by Prescription Strength
Prescription power can help narrow the selection, but it should never be the only factor. This chart shows reasonable material categories to compare, not mandatory prescribing rules.
| Approximate Sphere Power | Materials to Compare | Main Consideration |
|---|---|---|
| 0.00 to ±2.00 D | 1.50 / 1.59 / 1.60 | Standard materials may already look thin in a suitable frame |
| ±2.00 to ±4.00 D | 1.59 / 1.60 / 1.67 | Index and frame choice may improve cosmetic appearance |
| ±4.00 to ±6.00 D | 1.60 / 1.67 / 1.74 | Edge or center thickness can become a more significant concern |
| Above ±6.00 D | 1.67 / 1.74 | Individual thickness estimates and frame dimensions become particularly important |
Cylinder and axis influence thickness. Two prescriptions with the same sphere value may produce different lens profiles. These broad categories are a starting point only.
Prescription Differences
Edge Thickness vs Center Thickness: What's Different?
Minus Lenses: Edge Thickness
Lenses correcting nearsightedness generally have thinner centers and thicker edges. Their visible edge thickness is influenced by the frame's size, shape and eye positioning.
Plus Lenses: Center Thickness
Lenses correcting farsightedness generally have thicker centers and thinner edges. Lens diameter, design and required edge thickness can influence the center.
Beyond Lens Index
5 Factors That Can Change Your Lens Thickness
Prescription Strength
Higher optical powers generally require more curvature and can increase thickness.
Frame Size
Oversized frames can make strong minus lenses look thicker at the edges.
PD and Centration
Pupil position within the frame influences how much lens material is required.
Astigmatism
Cylinder power and axis change lens thickness across different meridians.
Lens Design
Aspheric designs, base curves and minimum thickness specifications affect results.
Need a Personal Comparison?
A meaningful estimate uses your full prescription, frame measurements and intended lens design.
Request a Lens Quote →Choosing Lens Materials
1.67 vs 1.74: Is the Upgrade Worth It?
This is one of the most common decisions for customers with strong prescriptions. The higher 1.74 index can offer additional thinning, but the visible improvement may be modest depending on the frame and prescription.
Reasons to Consider 1.67
- Strong prescription with a suitable frame
- Good balance of profile and budget
- Preference for available designs and treatments
- Smaller frames that help manage thickness
Reasons to Consider 1.74
- Very strong prescription power
- Greater priority on reducing lens bulk
- Compatible prescription and lens design
- Willingness to pay for a premium material
Different lens materials have different densities and optical dispersion. Consider anti-reflective coatings, material suitability, frame style and prescription accuracy alongside thickness.
Frame Selection
Can the Right Frames Make Your Lenses Thinner?
Often, yes. For minus prescriptions, choosing a smaller frame with appropriate eye positioning can reduce the distance from the optical center to the outer edge of the lens.
This can make the finished lens look substantially slimmer, even without choosing the highest refractive index.
If you already have a favorite frame, ask whether a different lens material can help before replacing it.
Frame Features to Review
- Lens width and vertical depth
- Overall frame shape
- Position of the pupils
- Full-rim vs rimless construction
- Material and minimum edge thickness
- Frame fit and comfort
Keep Your Frames
Can You Replace Thick Lenses With Thinner Ones?
You may be able to install higher-index prescription lenses in your existing glasses, provided the frame is suitable. A new material or lens design can improve the profile without requiring a new frame purchase.
What May Be Upgraded?
- Lens material and refractive index
- Compatible optical lens design
- Anti-reflective or other suitable coatings
- Updated prescription when available
What Determines Feasibility?
- Frame structure and condition
- Lens shape and dimensions
- Frame mounting requirements
- Prescription and fitting measurements
Prescription Lens Shopping
Shop Prescription Lenses and High-Index Options
Explore suitable lens categories after comparing lens thickness and material options.
Single Vision
Prescription lenses for one primary viewing distance.
Shop Single Vision →Progressive Lenses
Multifocal designs for distance, intermediate and near vision.
Shop Progressives →High-Index Lenses
Compare thinner materials and learn about high-index options in San Francisco.
Explore High Index →Want a Comparison for Your Own Prescription?
Upload your complete prescription and provide your frame details. CV Optical can review suitable lens material options and pricing.
Local Optical Guidance
Lens Thickness Comparison in San Francisco
Clear Vision Optical helps customers review prescription lenses, frame selection and material options. Visit our San Francisco store or browse lens categories online.
What to Bring for a More Useful Comparison
- Your complete prescription, including cylinder and axis
- PD or fitting measurements if available
- The frames you want to use
- Any concerns about edge or center thickness
- Your preferred price range
Frequently Asked Questions
Lens Thickness Comparison FAQ
Which eyeglass lens material is the thinnest?
How much thinner is 1.67 than 1.50?
Is 1.74 noticeably thinner than 1.67?
How thick will my lenses be at −5.00?
Does polycarbonate make lenses thinner?
Are thinner lenses always lighter?
Does frame size affect lens thickness?
Can I replace thick lenses in existing frames?
Compare Your Lens Options Before You Buy.
Explore high-index prescription lenses, keep compatible existing frames, or request a personalized lens recommendation from CV Optical.
