Organic Lens Materials: CR39, MR Resins, Polycarbonate, and Trivex

This page first focuses on the material: it determines impact resistance, clarity, density, and frame compatibility. Then, each material is linked to its index (1.50, 1.60, 1.67, 1.74…) to indicate thinning. If you are looking for a page focused solely on indexes, consult our dedicated guide.

1The Main Families of Organic Materials

CR39 Associated Index: 1.50

Standard, economical, and lightweight material; good optical performance for low to moderate corrections. Compatible with hard coating, anti-reflective, tints, photochromic. For very thin, nylor, or rimless frames, an MR resin is often preferred for superior thinning.

Comfort and controlled budget
"Standard" thickness

Typical index: 1.50
Thin alternative: MR-8 (1.60)

MR Resins (thiourethane) Indexes: 1.60 / 1.67 / 1.74

Designed for thinning while maintaining good mechanical strength. Relevant for thin, nylor, and often rimless frames (depending on geometry).

MR-8 → 1.60: versatile (thinness/strength)
MR-7 / MR-10 → 1.67: thinner for high corrections

MR-174 → 1.74: ultra-thin for very strong ametropia
Rimless compatibility: favorable (to be validated depending on the frame)

Polycarbonate Native Index: 1.59 (on request)

Reference for impact resistance (children, sports, safety) with intrinsic UV filtration. A quality hard coating is recommended to limit micro-scratches.

On Visionet: select 1.60 then indicate "Polycarbonate 1.59" after payment (identical price)

Trivex (PNX) Native Index: 1.53 (on request)

Excellent impact resistance, low density (very light), and good clarity. Reference for rimless frames and active uses where safety is paramount.

On Visionet: select 1.60 then indicate "Trivex 1.53" after payment (identical price)

To remember: first choose the material (use, robustness, frame compatibility), then the index to adjust the thickness.

2Quick Comparison of Organic Materials

Material	Associated Index	Strengths	Limitations	Recommended Uses
CR39	1.50	Comfort, contained cost, reliable optical performance	Thicker than high index lenses	Daily use, low to moderate corrections
MR-8	1.60	Good balance of thinness/strength, versatile	Less thin than 1.67/1.74	Thin/nylor frames, rimless (depending on geometry)
MR-7 / MR-10	1.67	Significant thinning, discreet appearance	Higher cost than 1.60	Strong corrections, aesthetics
MR-174	1.74	Ultra-thin, ideal for strong prescriptions	Higher budget, mounting precautions	Very strong corrections, large frames
Polycarbonate	1.59 (on request)	Impact resistance, native UV, lightweight	Requires careful hard coating	Children, sports, safety
Trivex	1.53 (on request)	Lightness, clarity, durability in rimless frames	Less thin than 1.60/1.67/1.74	Rimless frames, active uses

3Which material for your needs?

Comfort & budget: CR39 (1.50). For thin/nylor/rimless frames, switch to MR-8 (1.60).
Aesthetics (thinness): MR resins — MR-8 (1.60), MR-7/10 (1.67) if correction increases, MR-174 (1.74) for ultra-thin.
Robustness & safety: Polycarbonate (1.59) or Trivex (1.53), perfect for children, sports, rimless frames.

4Recommended Treatments (all materials)

Anti-scratch hard coating: longevity
Anti-reflective: contrast and comfort (screens, night driving)
Tints & polarization: anti-glare for road/sea/snow
Photochromic: clear indoors, dark in the sun

5Common Mistakes to Avoid

Choosing a high index without considering the material and frame
Forgetting impact resistance for child/sport use
Ignoring the impact of frame shape on perceived thickness

6Ordering Polycarbonate (1.59) or Trivex (1.53) on Visionet

Select index 1.60 (closest in thinning, identical price), confirm the order, then indicate "Polycarbonate 1.59" or "Trivex 1.53". Our workshop adapts the manufacturing without extra cost.

7Glossary (useful materials & concepts)

CR39: "Standard" organic resin linked to index 1.50: comfort, contained cost, standard thickness.
MR Resins: High-index family (1.60 / 1.67 / 1.74) designed for thinning while maintaining good strength.
Polycarbonate: Very impact-resistant, native UV. Index 1.59 (on request); ideal for children, sports, safety.
Trivex (PNX): Light, clear, robust. Index 1.53 (on request); very suitable for rimless frames.
Index: Ability of a lens to be thinned; the higher the index, the thinner the lens can be for the same correction.
PD (Pupillary Distance): Distance between the centers of the pupils, used for precise lens centering.
Rimless / Nylor Frame: Without full rim / semi-rimless; requires good mechanical strength of the material.
Photochromic: Lenses that darken in the sun and become clear indoors.
Polarization: Filter reducing glare (road, sea, snow) and improving contrast.
Hard Coating / Anti-reflective: Hard coating: limits micro-scratches. Anti-reflective: increased transparency and comfort.

8To go further

Compare with mineral: mineral lenses
Material details: polycarbonate lenses
Choose a suitable frame: eyeglasses

FAQ – Organic Lens Materials

CR39, MR Resins, Polycarbonate, Trivex: what are the main differences?

CR39 (index 1.50): comfortable and economical standard. MR resins (1.60/1.67/1.74) are used for thinning while maintaining good strength. Polycarbonate (1.59) and Trivex (1.53): prioritize impact resistance and lightness, adapted for children, sports, and rimless frames.

Which material for a rimless frame?

MR-8 (1.60) and Trivex (1.53) are very good candidates thanks to their mechanical strength. Polycarbonate may also be suitable depending on the frame geometry.

I want very thin lenses: what choice?

Opt for MR resins: MR-8 (1.60) for a good compromise, MR-7/10 (1.67) if the correction is stronger, MR-174 (1.74) for ultra-thin.

How to order in Polycarbonate (1.59) or Trivex (1.53)?

Select 1.60 in the configurator (identical price), confirm your order, then indicate your preference. Our workshop adjusts manufacturing without extra cost.

What treatments do you recommend?

Anti-scratch hard coating, anti-reflective, tints with polarizing option for anti-glare, and photochromic for alternating indoor/outdoor.

Difference with mineral lenses?

Mineral lenses offer excellent scratch resistance and very good clarity but remain heavier and more brittle than organic lenses. See: mineral lenses.

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Last updated on October 21, 2025 — Editorial: Visionet.