HIGH-INDEX LENS GUIDE

Thin & Ultra-Thin Lenses for Strong Prescriptions

Strong prescriptions do not automatically have to mean bulky-looking glasses. The right combination of high-index lens material, frame size, lens design and optical measurements can help reduce visible lens thickness.

Compare 1.60, 1.67 and 1.74 high-index lenses, understand why strong prescriptions become thick, and learn which factors can make the biggest difference before ordering new lenses.

QUICK ANSWER

Can Strong Prescription Glasses Be Made Thinner?

Often, yes. When a prescription produces thick lenses, choosing an appropriate high-index material can reduce visible bulk. Frame dimensions and optical positioning can be just as important as the lens material itself.

The best result usually comes from evaluating the prescription, frame and lens material together rather than selecting a lens index from prescription power alone.

01

Why Do Strong Prescription Lenses Look Thick?

Minus and plus prescriptions create thickness in different parts of the lens.

MINUS PRESCRIPTIONS

Thicker Toward the Edges

Strong minus prescriptions are thinner through the center and become thicker toward the outside of the lens.

Larger frames can require more lens area away from the optical center, making edge thickness more noticeable.

PLUS PRESCRIPTIONS

Thicker Toward the Center

Plus lenses generally require more thickness through the center. Lens diameter, frame dimensions and lens design can influence the amount of material required.

Proper frame selection can therefore matter for both strong plus and strong minus prescriptions.

02

What Determines How Thick Your Lenses Will Be?

1

Prescription

Stronger lens powers generally require more curvature or thickness.

2

Lens Material

Higher refractive indexes can allow a prescription to be produced using less material.

3

Frame Size

Smaller frames can significantly reduce visible thickness in many stronger prescriptions.

4

Optical Position

PD, decentration and lens design affect the final geometry of the finished lens.

03

1.60 vs 1.67 vs 1.74 High-Index Lenses

Higher index means the material bends light more efficiently, which can help reduce thickness in appropriate prescriptions.

Material Positioning Main Advantage When to Consider
1.50 Standard Plastic Traditional lens material Practical where thickness is not a major concern Lower prescriptions or situations where high-index material is unnecessary
1.60 Thin Lens Step above standard plastic Moderate thickness reduction When the prescription and frame call for a thinner material without automatically moving to 1.67
1.67 High Index Popular strong-prescription option Greater thickness reduction than lower-index materials in many appropriate prescriptions Stronger prescriptions where visible thickness is an important cosmetic concern
1.74 Ultra High Index Higher-index option Can provide additional thickness reduction Strong prescriptions where maximizing practical thinness is a priority and the required lens is available
Important: Exact finished lens thickness cannot be predicted from prescription power alone. Frame dimensions, frame shape, PD/decentration, lens design, minimum thickness requirements and fabrication all affect the result.

View the Complete Lens Thickness Comparison →

04

Should You Choose 1.67 or 1.74?

The highest refractive index is not automatically necessary for every strong prescription.

When 1.67 May Make Sense

  • You have a stronger prescription
  • Visible thickness is an important concern
  • You want a high-index material
  • Your chosen lens design is available in 1.67
  • Your frame works well with the prescription

When 1.74 May Be Worth Considering

  • Your prescription is particularly strong
  • Maximum practical thickness reduction is a priority
  • The frame can benefit from the higher index
  • The required lens design is available in 1.74
  • You understand frame choice still affects the final result
05

Frame Choice Can Make Strong Prescription Lenses Look Thinner

Lens material is only one part of the finished result.

Smaller Frames

Smaller lens openings can reduce the amount of lens extending away from the optical center.

Full-Rim Frames

Full rims can help conceal part of the lens edge in stronger minus prescriptions.

Good Eye Position

Keeping the eyes reasonably centered in the lens openings can reduce unnecessary decentration.

!

Avoid Unnecessary Size

Oversized frames can increase visible thickness even when high-index material is selected.

COMMON SEARCH QUESTION

Can You Thin Thick Prescription Lenses?

If finished prescription lenses are already too thick, they generally cannot simply be ground thinner while preserving the same optical properties.

The practical solution is normally to manufacture new prescription lenses using a more appropriate lens material, frame configuration or lens design.

Eyeglass Lens Replacement →
06

What About a –4.00 Prescription?

If your prescription is around –4.00 and you are specifically deciding between lens materials, we created a dedicated guide explaining the factors that influence the choice.

Best Lenses for a –4.00 Prescription →
07

Thin Lenses for Strong Progressive Prescriptions

Many progressive lens designs can also be produced in high-index materials. The appropriate material depends on the complete prescription, ADD power, frame measurements, progressive design and available lens options.

High-index material should therefore be considered together with the progressive design rather than simply choosing the highest refractive index available.

Explore Progressive Lenses →
08

Anti-Reflective Coating for High-Index Lenses

High-index materials can produce more noticeable surface reflections than standard plastic. A quality anti-reflective coating can reduce distracting reflections and improve the cosmetic appearance of the lenses.

Learn About Anti-Reflective Coating →
09

Thin Lenses for Frames You Already Own

Needing thinner lenses does not automatically mean buying completely new glasses.

Keep Your Existing Frames

If your current frame is suitable for relensing, new prescription lenses can be installed in frames you already own.

Eyeglass Lens Replacement →

Bought New Frames Somewhere Else?

You can also send eligible new frames purchased elsewhere and have prescription lenses installed in them.

Add Prescription Lenses to Frames →
10

Related Lens Guides

FAQ

Thin Lens Questions

Are high-index lenses thinner for strong prescriptions?

High-index materials bend light more efficiently than standard plastic, which can allow a strong prescription to be manufactured with less thickness. Frame size, optical measurements and lens design also affect the final result.

What is the thinnest lens material for a strong prescription?

1.67 and 1.74 are commonly considered when reducing lens thickness is an important goal. The most appropriate material depends on your complete prescription, lens type and frame.

Is 1.67 or 1.74 better for a strong prescription?

1.67 is suitable for many stronger prescriptions. 1.74 can offer additional thickness reduction in appropriate situations, but the actual benefit depends on the prescription, frame and lens design.

Can thick prescription lenses be made thinner?

New lenses can often be made thinner by using an appropriate high-index material, frame and lens design. Existing finished prescription lenses generally cannot simply be shaved thinner without affecting their optical properties.

What frames are best for strong minus prescriptions?

Smaller full-rim frames with the eyes positioned reasonably close to the center of the lens openings can help reduce visible edge thickness.

Can progressive lenses be made with high-index material?

Many progressive designs are available in high-index materials. Material selection depends on the prescription, progressive design, frame measurements and available lens options.

READY WHEN YOU ARE

Replace Thick Lenses Without Replacing the Frames You Love

Choose your prescription lens options and send us your eligible existing frames — or send eligible new frames purchased elsewhere.