1.5 vs 1.59 Index Lenses: Which One Is the Better Choice for Your Glasses?

When shopping for prescription glasses, lens material is just as important as the frame. Two of the most common options are 1.50 index lenses and 1.59 index lenses. Although their refractive index values appear similar, these two lens types are made from different materials and offer distinct advantages in terms of weight, impact resistance, thickness, and everyday performance.

In this guide, we'll compare 1.5 vs 1.59 index lenses to help you determine which option best suits your vision needs and lifestyle.

1.50 index lenses, also known as standard CR-39 plastic lenses, are the most widely used prescription lens material. They provide excellent optical clarity and are ideal for people with low prescription strengths.

1.59 index lenses are made from polycarbonate, a material originally developed for aerospace and industrial safety applications. These lenses are significantly more impact-resistant than standard plastic lenses while remaining relatively lightweight.

Unlike CR-39, polycarbonate naturally blocks nearly 100% of harmful UV rays, making it an excellent choice for active lifestyles.

One of the main reasons people upgrade to 1.59 lenses is the reduction in lens thickness.

For moderate prescriptions, 1.59 lenses can be approximately 8–12% thinner than 1.50 lenses. Although the difference may not be dramatic for mild prescriptions, it becomes more noticeable as prescription strength increases.

However, if your prescription exceeds ±4.00D, even thinner high-index options such as 1.60, 1.67, or 1.74 lenses may provide a better cosmetic appearance.

If visual clarity is your top priority, 1.50 CR-39 lenses generally have the advantage.

CR-39 has an Abbe value of approximately 58, while polycarbonate is around 30. A higher Abbe value means less chromatic aberration, resulting in sharper peripheral vision and better optical performance.

For most everyday wearers with low prescriptions, the difference may not be noticeable, but users with sensitive vision may prefer CR-39.

This is where 1.59 polycarbonate lenses clearly outperform standard plastic.

Polycarbonate is nearly unbreakable under normal daily use, making it the preferred material for:

• Children's eyewear
• Sports glasses
• Industrial safety glasses
• Protective eyewear
• Rimless frames

Because of its strength, polycarbonate lenses are much less likely to crack if accidentally dropped.

Both materials are lightweight, but polycarbonate has a lower density.

As a result, 1.59 lenses generally feel lighter, especially in larger frames or stronger prescriptions.

For people who wear glasses all day, the reduced weight can improve long-term comfort.

Cost is another important factor.

Generally speaking:

• 1.50 index lenses are the most affordable prescription lens option.
• 1.59 polycarbonate lenses cost slightly more because of their advanced material and superior durability.

For many users, the added impact resistance and UV protection justify the modest price difference.

The choice between 1.5 vs 1.59 index lenses depends on your prescription, budget, and daily activities.

If you prioritize optical clarity and affordability, 1.50 CR-39 lenses remain an excellent choice for low prescriptions. If durability, impact resistance, and UV protection are more important, 1.59 polycarbonate lenses offer significant advantages, especially for children, athletes, and anyone with an active lifestyle.

Before making a decision, consult your eye care professional or lens supplier to ensure the material matches both your prescription and the type of eyewear you plan to wear.