The Differences Between Plastic and Polycarbonate Lenses: A Comprehensive Guide
When choosing lenses for your eyeglasses or sunglasses, you may come across the terms 'plastic lenses' and 'polycarbonate lenses'. Both offer different advantages and disadvantages, making them suitable for different uses and preferences. This comprehensive guide will break down the key differences between plastic and polycarbonate lenses to help you make an informed decision.
1. Material Composition
Plastic lenses, typically made from CR-39, are a type of plastic known for their lightweight and good optical clarity. On the other hand, polycarbonate lenses are made from polycarbonate resin, a thermoplastic known for its strength and impact resistance.
Plastic Lenses: Made from CR-39, a type of plastic.
Polycarbonate Lenses: Made from polycarbonate resin, a type of thermoplastic.
2. Weight
When it comes to weight, plastic lenses are generally lighter than glass lenses but heavier than polycarbonate lenses. This weight difference can be significant for individuals who wear glasses or sunglasses for extended periods. The lighter weight of polycarbonate lenses makes them more comfortable for prolonged wear.
Plastic Lenses: Lighter than glass but heavier than polycarbonate.
Polycarbonate Lenses: Significantly lighter than both glass and plastic, making them more comfortable for long-term wear.
3. Durability and Impact Resistance
The durability and impact resistance of lenses are crucial factors to consider, especially for individuals who engage in high-impact activities. While plastic lenses are durable, they are more prone to scratches and breakage compared to polycarbonate lenses. Polycarbonate lenses are highly impact-resistant and less likely to shatter, making them a popular choice for safety glasses and children's eyewear.
Plastic Lenses: More durable but prone to scratches and breakage.
Polycarbonate Lenses: Highly impact-resistant and less likely to shatter, making them suitable for safety and children's eyewear.
4. Optical Clarity
Optical clarity is another important consideration. Plastic lenses offer excellent optical clarity and are less prone to distortion. Polycarbonate lenses, while providing good optical quality, may have slightly more distortion, especially in higher prescriptions. However, this difference is usually minimal and is often not noticeable to the naked eye.
Plastic Lenses: Excellent optical clarity with less distortion.
Poicycarbonate Lenses: Good optical quality but may have more distortion, especially in higher prescriptions.
5. Scratch Resistance
Scratch resistance is a key factor for those who wear glasses or sunglasses frequently. Both plastic and polycarbonate lenses can be coated with scratch-resistant treatments. However, polycarbonate lenses are more naturally scratch-resistant compared to plastic lenses.
Plastic Lenses: Can be coated with scratch-resistant treatments but are inherently less scratch-resistant.
Polycarbonate Lenses: More resistant to impact but can scratch more easily unless treated with a scratch-resistant coating.
6. Cost
The cost is another factor to consider when choosing between plastic and polycarbonate lenses. Plastic lenses are generally less expensive, making them a more cost-effective option for general use. However, polycarbonate lenses are slightly more expensive due to their advanced material properties and durability.
Plastic Lenses: Generally less expensive.
Poicycarbonate Lenses: Slightly more expensive due to their advanced material properties and durability.
7. UV Protection
UV protection is crucial for both safety and eye health. While plastic lenses offer some UV protection, they may require additional coatings for full UV blocking. Polycarbonate lenses naturally block 100% of harmful UV rays, making them an excellent choice for outdoor use.
Plastic Lenses: Offer some UV protection but may require additional coatings for full UV blocking.
Poicycarbonate Lenses: Naturally block 100% of harmful UV rays, making them suitable for outdoor use.
Summary
Polycarbonate lenses are often preferred for their lightweight and impact-resistant properties, making them suitable for active lifestyles, children, and safety applications. On the other hand, plastic lenses provide excellent optical clarity and are often more affordable, making them suitable for general use. The choice between the two will depend on individual needs, lifestyle, and preferences.
When making your choice, consider factors such as weight, durability, optical clarity, scratch resistance, cost, and UV protection. This guide should help you understand the differences between plastic and polycarbonate lenses, allowing you to choose the best option for your specific needs.