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1.55 Index Lenses (Polycarbonate Lite)
Starting from$39
1.55 index lens material — slightly thinner than CR-39 standard lenses. A budget step-up for low prescriptions wanting marginally thinner lenses.
1.55 Index Overview
1.55 index lenses are a modest step up from standard CR-39 (1.50). They produce lenses that are approximately 10% thinner and lighter than standard for the same prescription.
When to Choose 1.55
1.55 index is most appropriate for very mild prescriptions (under ±1.50) where CR-39 is already thin but you want the added thinness benefit without the cost of a higher index. For prescriptions above ±2.50, the 1.60 or 1.67 index offers a much more noticeable difference.
Comparison to CR-39
- ~10% thinner than CR-39 at equivalent prescription
- Slightly lighter weight
- Comparable optical clarity
- Higher cost than standard CR-39
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 1.55 Index Lenses (Polycarbonate Lite)
Order through LensesRx.com — choose the option that fits your situation.