Do Plastic Eyeglass Lenses Block UV Light?

Many people wonder if plastic eyeglass lenses provide adequate protection from harmful ultraviolet (UV) rays. The good news is that most plastic lenses, including those made from polycarbonate and Trivex materials, naturally block a significant amount of UV light. However, it is important to understand that not all plastic lenses offer full UV protection unless they are specifically designed to do so.

Understanding UV Light Blocking Capabilities of Plastic Lenses

Polycarbonate and Trivex lenses are among the best options for UV protection. These materials inherently block a substantial portion of UV light, making them ideal choices for individuals who spend significant time outdoors. However, other types of plastic lenses may not offer the same level of protection. For instance, CR-39 lenses, which are commonly used for everyday glasses, also block UV light, but typically require additional treatments to ensure complete UV protection.

Enhancing Protection with UV Coatings

While many plastic lenses inherently block a large amount of UV light, adding a UV-blocking dye can provide an extra layer of protection. This dye coats the lens surface and ensures that the lenses block 100% of UVA and UVB rays. This is an especially useful addition for those who spend long hours outdoors or in sunny climates. Additionally, photochromic lenses, which darken when exposed to sunlight, also provide 100% UV protection without the need for an extra UV treatment.

Choosing the Right Eyzeglass Lenses for Optimal UV Protection

For those who prioritize the highest level of UV protection, it is advisable to opt for lenses that explicitly state that they block 100% of UVA and UVB rays. When shopping for eyeglasses, pay attention to the labeling. Labels that mention 'UV-blocking' or lenses that have a clear UV coating offer the best protection. Many optical shops offer these lenses as an option, often at an additional cost, but the investment can be worth it for those who value complete UV protection.

Additional Considerations for UV Protection

In addition to the materials used, almost all spectacle glasses made from different plastics (not glass) block about 95 to 98% of UV light. However, it is important to note that outside reflections, side radiation, and top reflections can still allow up to 8 to 10% of UV light to enter your eyes. This is where special UV coatings can offer an additional layer of security.

Conclusion

In summary, while most plastic eyeglass lenses offer significant natural UV protection, it is crucial to ensure that the lenses offer complete or near-complete UV blocking. This can be achieved by choosing lenses from materials like polycarbonate, Trivex, and other treated or specially coated plastic lenses. For the best protection, opt for lenses labeled as UV-blocking or those with added UV coatings. Remember, the scientific evidence supports the benefits of UV protection in eyeglass lenses, and the cost of added UV protection is generally worth the investment for safety and long-term eye health.

If you have more specific questions or concerns about UV protection in your eyeglasses, consult with an optician or ophthalmologist for personalized advice.