Why Lens Index Matters When Choosing Glasses?
Not all lenses are created equal—especially when it comes to thickness and strength. If you have a stronger prescription or simply want a sleeker, lighter lens, understanding lens index is essential. The index of refraction (also called lens index) affects how thick or thin your lenses will be. Two of the most popular options for high prescriptions are 1.61 and 1.67 index lenses. But which is right for you?
What Is a Lens Index?
Lens index measures how efficiently a lens bends light. The higher the number, the thinner the lens can be for the same prescription. Standard plastic lenses are usually 1.50, while high-index lenses start at 1.60 and go up from there.
Here's how 1.61 and 1.67 compare:
| Lens Index | Thickness | Prescription Suitability | Weight | Cost |
|---|---|---|---|---|
| 1.61 | Thinner than standard lenses | Up to -5.00 | Lightweight | More affordable |
| 1.67 | Up to 20% thinner than 1.61 | -5.00 and higher | Ultra lightweight | Slightly more expensive |
Who Should Choose 1.61 High-Index Lenses?
1.61 index lenses are ideal for people with moderate prescriptions (roughly -2.00 to -5.00 or +2.00 to +4.00). They offer:
- A balance between cost and aesthetics
- Durable material for everyday use
- Better cosmetics compared to standard lenses
They're also great for semi-rimless or full-frame glasses where slight lens thickness isn't an issue.
When Is 1.67 Index the Better Choice?
1.67 high-index lenses are best for higher prescriptions (above -5.00 or +4.00). Benefits include:
- Significantly thinner edges, even in strong prescriptions
- Reduced "bug-eye" or "tiny eye" distortion
- Lighter glasses overall, which improves comfort
These lenses are particularly helpful for those choosing large or thin metal frames where lens thickness would be more noticeable.
Does Thinner Always Mean Better?
Not necessarily. While 1.67 lenses are thinner, they can be more reflective without the right coating. They may also be slightly less impact-resistant than 1.61 lenses. That's why high-index lenses—especially 1.67—should always come with anti-reflective coating to reduce glare and improve clarity.
Payne Glasses: Thin, Affordable High-Index Options
At Payne Glasses, we make it easy to upgrade to high-index lenses without breaking your budget. Whether you're looking for 1.61 lenses for everyday wear or need 1.67 lenses for stronger prescriptions, our options include:
- Free anti-scratch coating
- Anti-reflective lens upgrades
- Affordable pricing on premium thin lenses
Just upload your prescription, and we'll help you find the thinnest, most flattering lenses for your frame and prescription strength.