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1.67 High-Index Lenses
1.67 high-index lenses — 45% thinner than standard CR-39. Recommended for prescriptions above ±5.00 sphere or strong astigmatism corrections.
Starting from$69
1.67 High-Index Overview
1.67 index lenses are substantially thinner and lighter than standard lenses, making them the recommended choice for stronger prescriptions. At 45% thinner than CR-39, the difference is clearly visible.
Thickness Comparison
For a -6.00 sphere prescription:
- CR-39 (1.50): edge thickness ~12mm (very thick, owl-eye effect)
- 1.60 high-index: edge thickness ~9mm
- 1.67 high-index: edge thickness ~7mm — significantly more cosmetically acceptable
Best For
- Prescriptions from ±5.00 to ±8.00 sphere
- Strong astigmatism (cylinder above ±2.50)
- Patients who want the slimmest lens profile outside of 1.74
Weight
1.67 lenses are also lighter than 1.60 for equivalent thickness, contributing to all-day wearing comfort for stronger prescriptions.
Common Questions
How do I know which lens index I need?
As a general guide: up to ±2.50 — CR-39 works fine. ±2.50–±4.00 — consider 1.60. ±4.00–±6.00 — 1.67 recommended. Above ±6.00 — 1.74 is ideal.
Does higher index mean better optical quality?
Not necessarily. CR-39 has the lowest chromatic aberration of all plastic materials. Higher index materials have slightly higher chromatic aberration, though most wearers don't notice it.
Are high-index lenses more fragile?
High-index lenses have higher clarity but are slightly more brittle than polycarbonate. For impact-prone situations (sports, children), polycarbonate's toughness outweighs the thinness benefit.
Get 1.67 High-Index Lenses
Order through LensesRx.com — choose the option that fits your situation.