⚠️Medical Disclaimer: All tools on PDCalculator.net are for educational and informational purposes only. They do not replace professional eye care advice, diagnosis, or treatment. Always consult a licensed optometrist or ophthalmologist before purchasing eyewear or making any changes to your vision correction. Results are based on standard optical formulas and are provided as a general guide only.
📊 Lens Index Comparison
Index
Name
Best Rx Range
Thickness vs 1.50
Cost
1.50
Standard plastic (CR-39)
Up to ±2.00D
Baseline
💰 Cheapest
1.57
Mid-index
±2.00 to ±3.00D
~10% thinner
💰💰 Low
1.61
High-index
±3.00 to ±5.00D
~20% thinner
💰💰💰 Medium
1.67
High-index
±5.00 to ±7.00D
~30% thinner
💰💰💰💰 Higher
1.74
Ultra high-index
±7.00D and above
~40% thinner
💰💰💰💰💰 Premium
❓ Frequently Asked Questions
Is 1.67 high-index worth the extra cost? +
For prescriptions above ±4.00D, absolutely yes. The reduction in weight and edge thickness is dramatic — roughly 30% thinner than standard lenses. Many online retailers offer 1.67 high-index for just $30–50 extra over standard, which is very worthwhile for comfort.
Do higher index lenses distort vision? +
Higher index lenses have slightly higher chromatic aberration (color fringing), especially 1.74. However, with modern anti-reflective coatings and good optical design, this is barely noticeable for most wearers. The comfort and aesthetic benefits far outweigh any minor optical compromise.
Do I always need an anti-reflective coating with high-index lenses? +
Strongly recommended, especially for 1.67 and 1.74. Higher index materials reflect more light (higher reflectance), making AR coating almost essential for comfortable vision and acceptable appearance. Most retailers include it as standard.
My prescription is only −1.00 — do I need high-index lenses? +
No. At −1.00 with a standard frame size, even 1.50 standard lenses will be very thin (2–3mm edge thickness). High-index lenses would make almost no visible difference and are not worth the extra cost at low prescriptions.