When choosing glasses, the lens material is a key factor to consider. In the current lens market, plastic lenses and polycarbonate lenses are popular choices. Before making a purchase, it is important to consider their characteristics, advantages, disadvantages and etc. Different types of lens materials vary in weight, flexibility, durability, thickness, scratch resistance, and more. They also affect your vision, comfort, and appearance.
In this article, we will describe in detail the advantages, disadvantages, and differences between plastic lenses and polycarbonate lenses.
Overview of Plastic Lenses
What Are Plastic Lenses?
Plastic lenses first appeared in 1947. Since then, plastic has become a popular and widely used material for making eyeglass lenses. With the continuous advancement of technology, the manufacturing process of resin lenses has also been improved, allowing them to excel in optical performance and durability. Since the introduction and use of plastic lenses, they have become the preferred choice in the optical industry.
Plastic lenses, also known as CR39 lenses, derive their name from “Columbia Resin 39,” indicating that it was the 39th formulation of the resin. Compared to traditional glass lenses, plastic lenses are lighter and thinner, making them more comfortable. They also offer features such as impact resistance and UV protection. They are commonly used in corrective eyeglasses as well as non-corrective applications like sunglasses, fashion accessories, and sports goggles. As a result, they are widely used in the eyewear industry, meeting people’s demands for lightweight, comfortable, and high-quality vision.
The Advantages and Disadvantages of Plastic Lenses
Advantages
- Lightweight: Plastic resin lenses are lighter and thinner than glass lenses, making them very comfortable for long-term wear. The lightweight nature of plastic makes it an excellent material for eyeglass lenses, as it does not weigh heavily in glass frames and can be easily fitted into any type of frame.
- High Impact Resistance: Plastic lenses are very durable and offer higher impact resistance compared to glass lenses, making them less likely to break and safer. While plastic lenses are not as shatter-resistant as polycarbonate lenses, they are still a good choice for active individuals.
- Good Optical Clarity: Plastic lenses offer excellent optical performance with minimal visual distortion, providing clear vision and accurate correction.
- Affordability: The raw materials used to make plastic are relatively inexpensive and readily available in the required quantities. These products can also be quickly and cheaply shaped into the desired form. This makes plastic lenses cost-effective and reasonably priced.
Disadvantages
- Thickness: Compared to polycarbonate lens material, plastic lenses have a lower refractive index, so they are usually thicker. If your prescription is high, it can result in thick lenses that may not look aesthetically pleasing when mounted in the frame, and can be tiring to wear for long periods. It is recommended to choose high-index plastic lenses in such cases.
- Susceptible to Scratching: The surface of plastic lenses is soft and prone to scratching by sharp objects, so they need to be coated with an anti-scratch coating to form an additional protective layer. However, even with the addition of an anti-scratch coating, plastic lenses are still prone to scratching.
- Not Heat Resistant: Plastic resin lenses are not heat resistant and should not be placed in high-temperature environments. Prolonged exposure to high temperatures can cause the lenses to yellow and deform.
- Lack of UV Protection: Long-wave ultraviolet (UV) rays can easily pass through most plastic materials. Generally, UV rays with wavelengths between 350 nanometers and 400 nanometers can pass through plastic without the need for additional UV protection coatings. However, UV rays with wavelengths below 300 nanometers are absorbed. If you plan to wear your glasses outdoors, it is advisable to add a UV protection coating to achieve 100% protection.
Overview of Polycarbonate Lenses
What is Polycarbonate Lens?
Polycarbonate lenses are a type of eyeglass lenses made of polycarbonate material. They are lightweight, impact resistant and highly transparent, making them widely used in eyewear, sunglasses and safety glasses.
Polycarbonate is a tough plastic that was first discovered in the 1950s and was used in the space industry in the 1970s for astronauts’ helmet goggles and space shuttle windscreens. It wasn’t until the late 1970s and early 1980s that polycarbonate began to be used in the manufacture of eyeglass lenses. Its impact resistance makes it ideal for use in safety glasses, sports glasses and children’s glasses. Additionally, polycarbonate has excellent optical properties that provide clear vision, making it the preferred choice for many people’s everyday eyeglasses and sunglasses.
Polycarbonate Lenses Pros and Cons
Pros
- High Impact Resistant: Polycarbonate lenses are one of the most impact-resistant lenses on the market. They are more impact resistant than regular plastic lenses, making them less likely to shatter and therefore safer. They are especially suitable for children, sports enthusiasts, and those who need additional protection.
- Lightweight and Comfortable: Polycarbonate lenses have a higher refractive index, which means they are thinner and lighter than plastic lenses with the same power. This also makes them more comfortable for long-term wear.
- Versatility: Because polycarbonate lenses are so common, you’re likely to be able to get any lens feature you want. Whether you need polarized, progressive, or any other feature, polycarbonate lenses have you covered.
- UV protection: Polycarbonate blocks UV rays, so there is no need to add a UV coating to your glasses. These lenses are a good choice for people who spend a lot of time outdoors.
Cons
- Easily Scratched: Despite being durable, polycarbonate lenses are still prone to scratching and require regular cleaning and maintenance. It is recommended to use an anti-scratch coating to prolong the lifespan of the lenses.
- Poor Optical Clarity: To measure the clarity of various lens materials, we use something called the Abbe value. The higher the number, the clearer the lens. However, the Abbe value of PC lenses is 33, which means they have relatively poor clarity.
- Expensive: Polycarbonate lenses are typically more expensive than plastic lenses.
Plastic vs Polycarbonate Lenses: Which is Better?
From the above information, you may have learned some features of polycarbonate lenses and plastic lenses. So, do you know which one is better?
- Plastic lenses are cheaper than polycarbonate lenses.
- Plastic lenses are easy to tint compared with polycarbonate lenses which accept tints.
- Plastic lenses have a higher optical clarity than polycarbonate lenses.
- Polycarbonate lenses have inherent UV protection, while plastic lenses do not have.
- Polycarbonate lenses have higher impact resistance and offer greater protection than plastic lenses.
- Polycarbonate lenses are lighter than plastic lenses.
- Polycarbonate lenses are suitable for rimless frames, while plastic lenses can’t.
Finally, this article from Aogang Optical explains what polycarbonate glasses and plastic lens glasses are. If you have any different opinions about polycarbonate lenses and plastic lenses, let us know in an email and we’ll be happy to answer any questions you may have.
