No, polarized sunglasses are not all the same. The lenses can be made using different materials and construction methods which can affect their quality, performance and visual clarity. Polarized lenses can be made of acrylic, polycarbonate, CR39 (resin) and even mineral glass, all of which can be made to varying degrees of production standards.
For you, the wearer, this introduction may seem intricate and somewhat daunting. However, this article aims to make your lens decision as easy as possible.
Let's dive in.
Quick refresher: Polarized lenses use filters which blocks glare from flat reflective surfaces such as water, snow or wet roads. If they're UV40 rated, they also provide full ultraviolet protection against the sun's UVA and UVB rays (which is the most crucial function of any sunglasses frame).
Are there different types of polarized sunglasses?
There are 5 main types of polarized sunglasses which are categorised by their lens material. Ranging from low to high quality, these include acrylic, TAC, polycarbonate, CR39 and mineral glass. Depending on your budget, application and desired performance, most polarized sunglasses use these types of lenses.
Here's a helpful breakdown;
Type 1: Acrylic Polarized Lenses
Acrylic polarized sun lenses are recognized for their affordability, serving as the entry-level choice for those seeking polarized performance without a significant investment.
These lenses are mass manufactured by integrating a polarized film between two layers of acrylic material. This process involves the application of heat to stretch and mold the film to match the lens's spherical curvature before cutting it to shape.
Despite their cost-effectiveness, acrylic lenses are noted for their limitations, such as a higher susceptibility to scratches and the presence of peripheral distortion, particularly noticeable around the lens edges. This distortion can compromise the lens's polarizing effectiveness, making them less favorable if you prioritizing clarity and durability in their sunglasses.
Acrylic polarized lenses are best suited for general everyday use, where extreme conditions are not a factor. This makes them an excellent choice for casual outdoor activities or fashion purposes.
Type 2: TAC Polarized Lenses
TAC polarized sun lenses are one of the most common types of polarized lenses, best known for their lightweight properties and multi-layer construction.
Shortened to TAC, Tri Acetate Cellulose lenses are made from numerous layers and films including anti-scratch, anti-reflective, anti-distortion, UV and an in-built polariser film. Ranging between 5,7 or even 9 layers, they're all sandwiched together to make a highly efficient sun lens.
TAC lenses also be made to high base curvatures between 8 and 12 for wrap around, sports orientated sunglasses frames.
The main benefit of TAC lenses over acrylic is a much greater optical clarity which even outperforms polycarbonate polarized sun lenses. These lenses are lightweight, offer great visual clarity and protect your eyes from UV light.
However, TAC lenses cannot be made as prescription lenses and aren't anywhere near as impact resistant as polycarbonate. This makes them less suitable for sport or if you require optical correction with your lenses.
Type 3: Polycarbonate Polarized Lenses
Polycarbonate polarized sun lenses are hailed for their extreme durability and resistance to impact, making them a top choice for athletes and individuals involved in active outdoor activities. These lenses are constructed through an injection-molding process that ensures a robust build, capable of withstanding harsh conditions without compromising the integrity of the polarization. They can also be made to high base curvatures between 8 and 12 for wrap around sunglasses frames.
The prime advantage of polycarbonate material is its lightweight nature combined with superior strength, offering significant protection against UV rays and physical impact damage. However, despite these benefits, a drawback is the potential for optical distortion due to the way the lenses are manufactured, which can affect clarity for some wearers.
More scratch-resistant than laminated acrylic, polycarbonate lenses are best recommended for sports enthusiasts, outdoor adventurers and anyone engaged in activities where eye protection and durability is a critical concern.
Type 4: CR39 Polarized Lenses
CR39 polarized sun lenses are esteemed for their exceptional clarity, attributed to the high-quality process of laminating the polarized film between two resin-material lens layers. This method minimizes optical distortions and enhances the wearer's vision, unlike the potentially compromised clarity found in polycarbonate lenses.
While not as impact-resistant as their polycarbonate counterparts, CR39 (Columbia Resin recipe 39) lenses offers great levels of varying refractive index for mild to very strong prescriptions. They're also durable for everyday, non-sporting use, along with superior scratch resistance.
CR39 polarized lenses offer a commendable balance between performance and optical excellence, making them a favored choice for casual wear and light outdoor activities where clarity of vision is paramount but extreme durability is not as critical.
Type 5: Glass Polarized Lenses
Mineral glass polarized sun lenses stand at the pinnacle of optical performance. They offer unmatched clarity and supreme scratch resistance deriving from their manufacturing process that ensures minimal distortion of the polarized film.
These lenses maintain consistent polarized effectiveness across the entire lens' surface, providing superior glare reduction and visual comfort in intensely bright conditions.
However, despite their exceptional optical attributes, they tend to be heavier and more fragile compared to their plastic counterparts, making them less ideal for high-impact sports or activities where durability is a priority.
Given their premium clarity and resistance to wear, mineral glass polarized lenses are best suited for daily wear, driving, and outdoor activities where visual precision is crucial, but the risk of impact is minimal.
Choosing the right polarized lens material
When choosing the right polarized lens material for your needs, several critical factors should be taken into account to ensure that your selection not only enhances your vision but also suits your lifestyle and activities.
Durability: Consider how resistant the lens material is to impacts and scratches, especially if you lead an active outdoor life or engage in sports. For this reason, acrylic polarized lenses aren't particularly durable compared to polycarbonate or CR39 lenses.
Weight: Lens material can significantly affect the overall comfort of your sunglasses. Lightweight materials such as polycarbonate typically offer greater comfort for extended wear compared to that of mineral glass.
Optical Clarity: High optical clarity is essential for activities requiring precision vision, such as driving or sports. For general use, CR39 is by far the most prevalent lens material with fantastic optical clarity. For sports, polycarbonate is a safer option for impact resistance and weight saving properties.
UV Protection: Ensure that the polarized lenses are rated as UV400 to ensure they provide 100% UV protection to safeguard your eyes against harmful ultraviolet rays.
Cost: The price can vary widely between different lens materials, so consider your budget when making a decision.
Aesthetic Preferences: Some coatings such as mirrored lenses can alter the aesthetic of the glasses, which may be a consideration for those who prioritize style alongside functionality.
By carefully weighing these factors, you can select a polarized lens material that meets your vision needs, comfort preferences, and lifestyle demands.
Choosing between polarized lens colors
The color of the lens in polarized sunglasses plays a crucial role not only in fashion but also in function. Different lens colors are designed to serve various purposes, affecting visibility, contrast, and depth perception under varying light conditions.
Selecting the right lens color can enhance visual clarity and comfort, particularly in specific environments or activities. Whether it’s reducing glare on the water, improving contrast on the slopes, or providing all-day comfort in variable light conditions, understanding the significance of lens color can significantly impact your visual experience.
Gray Polarized Lenses
Gray polarized lenses are renowned for their versatility and universal appeal, making them a preferred choice for a wide range of scenarios. They excel in maintaining true color perception, crucial for activities where color differentiation is necessary.
By effectively reducing brightness without altering the color spectrum, these lenses protect the eyes from glare while preserving natural hues.
Ideal for driving, water sports, and general use in bright conditions, gray polarized lenses offer a balanced view that enhances visual comfort in both high-glare and standard lighting situations, making them an essential accessory for those seeking to combine functionality with style.
Pairs well with: Any color of sunglasses frame or clothing
Brown Polarized Lenses
Brown polarized lenses stand out for their ability to significantly enhance visual contrast and depth perception, making them ideal for conditions that fluctuate between light and shadow. These lenses work exceptionally well in enhancing the warmth and crispness of colors, providing an improved visual experience in both overcast and sunny conditions.
By filtering out haze and reducing glare, they offer superior clarity, making them perfect for activities such as fishing, golfing, and driving. The high contrast and visual comfort provided by brown polarized lenses make them a popular choice among those who prioritize clarity and depth in their outdoor pursuits.
Pairs well with: Tortoise shell, crystal or nude acetates.
Green Polarized Lenses
Green polarized lenses offer a unique balance by diminishing glare while enhancing contrast and sharpness in bright sunlight conditions. Historically significant for their use in reducing eye strain in aviation, these lenses provide a more natural color perception than other tinted lenses, which makes them particularly suited for outdoor activities where true color recognition is crucial.
The enhanced visual clarity and reduced glare make green polarized lenses an excellent choice for activities such as driving, fishing, and boating, where precise vision and comfort in various lighting conditions are essential.
Pairs well with: Black, tortoise shell or crystal acetates.
Alternative Polarized Lens Colors
Beyond the standard colors of gray, brown or green, there are many alternative tints available; especially from sports brands such as Oakley who offer their proprietary range of Prizm polarized lenses. If you're looking for sports sunglasses, they have a wide range of colors for you to choose from.
For more information about sunglasses tint colors, check out this handy blog post.
Key take aways
- Acrylic: an entry-level polarized lens option with moderate durability and scratch resistance.
- TAC: A great non-prescription polarized lens material for everyday use, driving and non-contact sports.
- Polycarbonate: Lightweight and impact-resistant, ideal for contact sports and active lifestyles.
- CR-39: Offers clear optics and is lighter than glass, suitable for everyday use.
- Glass: Provides superior clarity and scratch resistance, favored for its durability.
- Gray Polarized Lenses: Ideal for general use and everyday situations, offering balanced color perception and reducing brightness without altering natural colors.
- Brown Polarized Lenses: Enhances contrast and depth perception, making them suitable for sports like golfing or conditions with variable lighting.
- Green Polarized Lenses: Provides a natural color balance and reduces glare significantly, perfect for driving and outdoor sports where true color recognition is critical.
Hopefully you found this article helpful. If so, please check out our other polarised sunglasses blog posts for more helpful advice.
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