When choosing eyewear lenses, should you opt for glass lenses or polycarbonate lenses? Each type of lens has its unique set of advantages and disadvantages, suitable for different needs and preferences. If you have browsed through prescription or non-prescription eyewear, you know that both types of lenses offer their own benefits and drawbacks. So, which one is the best choice for you? In this article, we will explore the key characteristics, benefits, and drawbacks of polycarbonate and glass lenses to help you make an informed decision.
Polycarbonate Lenses
What Are Polycarbonate Lenses?
Polycarbonate lenses are a type of eyeglass lenses made from a strong and lightweight material called polycarbonate. The lenses are incredibly durable, able to withstand impact and rough handling without breaking. A polycarbonate lens is over 10 times more impact-resistant than your average plastic or glass lens. PC lenses are a versatile choice suitable for various activities, whether it’s for everyday wear, sports, or safety glasses. Their ability to offer both safety and comfort makes them a popular and practical option in the world of eyewear.
Polycarbonate Lenses 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.
Polycarbonate Lenses 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.
Glass Lenses
What Are Glass Lenses?
Glass lenses are a type of lens made from optical glass as the main raw material. Glass prescription lenses still offer the best visual acuity of any eyeglass lens, as they have for hundreds of years. Glass lenses typically boasts an index of refraction within the range of 1.523 to 1.7. These lenses are favoured for their superior optical properties, high light transmission, mechanical and chemical properties, and stable physicochemical properties. Glass lenses typically have a higher refractive index than resin lenses, which makes them more effective in correcting vision. They also have a higher surface hardness, making them more resistant to wear and tear. Although glass lenses are less prone to discolouration, they are relatively difficult to process and are often used for high-precision optical instruments such as telescopes and microscopes.
Glass Lenses Pros
Superior Optical Performance: Glass lenses offer exceptional optical performance with high light transmission, providing clearer and distortion-free vision with minimal aberrations.
Scratch Resistance: Glass is highly scratch-resistant, making glass lenses less prone to scratches during everyday use. This durability is particularly useful for individuals who frequently work outdoors or in challenging environments.
High Stability: Glass lenses are chemically stable and less affected by environmental changes, such as temperature fluctuations or exposure to chemicals. This means they maintain their performance over time without easily degrading.
Thin and Aesthetic: Glass lenses typically have a higher refractive index, which means they can be made thinner and more aesthetically pleasing.
Glass Lenses Cons
Heavier Weight: Glass lenses are relatively heavy, which can cause significant pressure on the nose and ears when worn for extended periods. Frameless or semi-frameless frames may not support the weight of glass lenses.
Fragility: Despite their scratch resistance, glass lenses have poor impact resistance and are prone to shattering. This not only increases the cost of replacement but also poses a safety risk, particularly for children or for glasses designed for sports like football or soccer.
Polycarbonate vs Glass Lenses
When deciding between polycarbonate and glass lenses, it is essential to consider your specific needs and lifestyle. Here are some key factors, such as optical clarity, scratch and impact resistance, weight, and UV protection, to help guide your decision:
- Optical Clarity: If optical clarity and minimal chromatic aberration are your top priorities, glass lenses offer the best visual acuity, which is why binoculars, telescopes, and cameras use it. They are ideal for individuals with high prescriptions or those who demand the highest quality vision.
- Scratch resistance: Glass and polycarbonate can both become scratched, but polycarbonate is much easier to scratch. While glass lenses are more scratch-resistant, modern polycarbonate lenses with scratch-resistant coatings offer a good balance between durability and performance.
- Impact resistance: A lens with high impact resistance is less prone to cracking or shattering. Both glass and polycarbonate lenses can endure occasional drops, though neither is indestructible. Glass lenses are more susceptible to breaking, while polycarbonate lenses are significantly more robust, offering 10 times the strength of glass.
- Weight: For those who wear glasses for extended periods, the lightweight nature of polycarbonate lenses provides superior comfort. Glass lenses, while optically superior, may cause discomfort due to their heavier weight. Polycarbonate is actually considered a lightweight lens material. The weight of your glasses is most noticeable through pressure at the nose pads and temple tips.
- UV Protection: Polycarbonate lenses offer built-in UV protection, making them a convenient option for those who spend a lot of time outdoors. Glass lenses can also provide UV protection but require additional coatings.
