The Differences Between PC Lenses and Resin Lenses

In the previous article, we learned what PC lenses are. This article will provide a detailed explanation of the differences between PC lenses and resin lenses.

PC lenses (polycarbonate) and resin lenses (typically referring to CR-39 or high-index resin) are currently the two most common types of lens materials on the eyewear market. Although they both fall under the broad category of "plastic," they differ significantly in terms of physical properties, safety, and suitability for different user groups.

Here is a comparison of their key features:

1. Impact Resistance and Safety (The Key Difference)
PC Lenses: Commonly known as "bulletproof glass." They are extremely tough and do not shatter easily when subjected to violent impacts; instead, they may dent or deform. Therefore, they offer the highest level of safety.
Resin Lenses: Although more impact-resistant than traditional glass lenses, they may still shatter under extremely strong impacts, making them slightly less safe than PC lenses.

2. Optical Performance (Clarity)
Resin lenses: The dispersion coefficient (Abbe number) is typically high (58 for CR-39). The higher the Abbe number, the lower the lens dispersion, resulting in sharper peripheral vision and greater visual comfort.
PC Lenses: The Abbe number is lower (typically around 30). This means they exhibit relatively high chromatic aberration; some people with heightened sensitivity may notice rainbow-colored halos at the edges of the lenses or experience mild visual fatigue.

3. Weight and Thickness
PC lenses: With a refractive index typically of 1.59 and a low material density, these lenses are very lightweight and thinner than standard 1.50 resin lenses.
Resin Lenses: The refractive index options range widely (1.50, 1.56, 1.60, 1.67, 1.74). At the same low refractive index, resin lenses are slightly heavier than PC lenses; however, for high prescriptions, ultra-high-index resin lenses (such as 1.74) can be made thinner than PC lenses.

4. Scratch Resistance
Resin Lenses: These have relatively good hardness and offer excellent scratch resistance when coated with a hardening coating.
PC Lenses: This material is relatively soft and extremely prone to scratches. Although they come with a scratch-resistant coating from the factory, they require more careful daily maintenance than resin lenses.

5. UV Protection
PC Lenses: The material itself provides 100% UV protection (UV400), so no additional UV-blocking coating is required.
Resin Lenses: Standard resins (such as CR-39) do not inherently provide complete UV protection; UV protection must be achieved through post-production coating or base material modification.

Comparison of Key Specifications

Summary: How Should You Choose?

Choose PC lenses if:
1. You frequently participate in sports (such as basketball or tennis), or if you're getting glasses for children or teenagers - safety comes first.
2. You plan to wear rimless or semi-rimless glasses. PC lenses are highly durable and less likely to crack when holes are drilled for screws.
3. You're extremely sensitive to the weight of your glasses and seek the ultimate in lightness.

Choose resin lenses if:
1. You use them for daily office work, reading, or driving, and have very high expectations for visual clarity and comfort (chromatic aberration correction).
2. You have a high prescription (e.g., over 600 diopters) and need high-index lenses (1.67 or 1.74) to keep the lenses thin.
3. You have a moderate budget, or you want lenses that are more scratch-resistant and last longer.