High index lenses are a good option if you have a stronger prescription and want your glasses to look thinner, feel lighter, and sit more comfortably on your face. At CV Optical in San Francisco, we help you choose the right lens material based on your prescription, frame style, and how you wear your glasses every day.
For many people with higher prescriptions, standard lenses can look thick around the edges or make the frame feel heavier than expected. High index lenses are made to reduce that thickness and create a cleaner, more natural look, especially when paired with the right frame shape.
Thinner Lenses for Stronger Prescriptions
If your prescription makes regular lenses look bulky, high index lenses may help improve both comfort and appearance. They are often recommended for customers who want a lighter pair of glasses without giving up clear vision or everyday durability.
Choosing the Right Lens Option
Not every prescription needs high index lenses, and not every frame is the best match for them. Our team at CV Optical can review your prescription, explain your lens options, and help you choose lenses that fit your frame, your comfort needs, and your daily lifestyle.
Visit CV Optical in San Francisco to compare high index lenses, coatings, and frame options before choosing your next pair of glasses.
High Index Lenses in San Francisco
If you wear a moderate or strong prescription, lens thickness affects both comfort and
appearance. At CV Optical in San Francisco, we offer 1.60 and 1.67 high index lenses
designed to reduce edge thickness while maintaining optical clarity.
Every pair is measured and fitted in person to ensure precision.
What Are High Index Lenses?
High index lenses are made from materials with a higher refractive index, meaning they
bend light more efficiently. Because they bend light more effectively, less material is
needed to achieve the same prescription power.
The result:
✔ Thinner lenses
✔ Lighter weight
✔ Improved cosmetic appearance
We offer:
• 1.60 High Index
• 1.67 High Index
• Polycarbonate (1.59)
Understanding Refractive Index
The refractive index measures how efficiently a lens material bends light.
• Polycarbonate: 1.59
• High Index 1.60
• High Index 1.67
The higher the refractive index, the thinner the lens can be for stronger prescriptions.
Prescription Examples: Real Thickness Differences
Here’s how material choice affects thickness:
-2.00 Prescription
1.60 provides mild thinning. Polycarbonate also works well for durability.
-4.50 Prescription
1.67 significantly reduces edge thickness compared to polycarbonate or 1.60.
-6.00 Prescription
1.67 is strongly recommended to reduce heavy edges and improve appearance.
-8.00 Prescription
1.67 combined with a smaller frame dramatically reduces thickness compared to standard
plastic.
Edge Thickness Explained
For minus prescriptions, lenses are thinner in the center and thicker at the edges.
Edge thickness depends on:
• Prescription strength
• Frame width
• Lens diameter
• Pupillary distance
• Vertex distance (distance between lens and eye)
Larger frames increase edge thickness dramatically.
Choosing the right frame size can reduce thickness as much as upgrading the lens material.
Frame Size Impact on Final Appearance
Example:
• -6.00 in a 56mm wide frame → noticeable thick edges
• -6.00 in a 48mm frame → significantly thinner appearance
Frame selection is part of professional lens planning.
Aspheric Design: Cosmetic Improvement
Many 1.67 high index lenses use aspheric design, which flattens the front curve of the lens.
Benefits:
• Reduces “bulging” effect
• Minimizes magnification distortion
• Creates slimmer side profile
Aspheric designs improve both cosmetics and optical performance.
Abbe Value & Optical Clarity
The Abbe value measures how much chromatic aberration (color fringing) a material
produces.
• Polycarbonate: Lower Abbe value
• 1.60: Balanced clarity
• 1.67: Slightly lower than 1.60 but thinner
For many prescriptions, 1.67 provides the best balance between thinness and visual clarity.
Polycarbonate vs High Index
Polycarbonate
Best for:
• Impact resistance
• Children
• Rimless or drill mount frames
Pros:
• Lightweight
• Extremely durable
Cons:
• Not as thin as 1.67
• Lower optical clarity compared to 1.60
1.60 High Index
Best for:
• -2.00 to -4.00 prescriptions
• Moderate thinning needs
1.67 High Index
Best for:
• Prescriptions stronger than -4.00
• Cosmetic edge reduction
• Professional appearance
Why Professional Measurement Matters
Even the best lens material performs poorly if improperly measured.
We measure:
• Pupillary distance
• Fitting height
• Pantoscopic tilt
• Vertex distance
These adjustments ensure clarity, comfort, and proper alignment.
Can You Put High Index Lenses in Old Frames?
Yes — if the frame is structurally sound and appropriately sized for your prescription.
However, smaller frames often produce better cosmetic results.
Book a Lens Consultation in San Francisco
All measurements are performed in person at CV Optical in San Francisco’s Financial
District.
If you want thinner lenses without compromising clarity, schedule a lens consultation today
