What Are UV Rays and Why They Matter
Ultraviolet (UV) rays are invisible rays of light that come primarily from the sun—and while we can’t see them, our eyes certainly feel their effects over time. There are three types of UV radiation:
UVA: These rays penetrate deep into the skin and eyes, causing long-term damage. They make up about 95% of the UV radiation that reaches us.
UVB: These rays are more intense and can cause immediate damage like sunburn or snow blindness (photokeratitis). They are also linked to cataracts and growths on the eye.
UVC: The most dangerous, but thankfully, they’re filtered out by the Earth’s atmosphere.
Why UV Rays Matter
Living in Calgary means more sun exposure than many other parts of Canada—over 330 sunny days a year. That might sound great for your mood, but it increases your eyes' daily exposure to harmful UV rays. Given the city’s high elevation and long winters with reflective snow, your eyes are exposed to UV rays year-round—even on cloudy days.
Unchecked UV exposure can lead to:
Cataracts: Clouding of the lens that affects vision over time
Macular degeneration: A leading cause of vision loss in older adults
Photokeratitis: A painful sunburn of the eye (often called “snow blindness”)
Protecting your eyes from UV isn’t just about comfort—it’s about long-term vision health.
How UV-Blocking Glasses Work
Not all glasses protect your eyes from the sun. To block UV rays, the lenses need to have special materials or coatings that stop those harmful rays from reaching your eyes.
Some lenses protect by default
Certain lens materials—like polycarbonate and Trivex—block 100% of UV rays on their own. These are often used in safety glasses and children’s eyewear because they’re light, strong, and naturally protective.
Others need a UV coating
Standard plastic lenses don’t always block UV rays by themselves. That’s why many lenses have a clear, invisible coating added to them. When labeled “UV400,” it means the lenses block nearly all UV rays—including both UVA and UVB.
UV can sneak in from behind
Sunlight reflects off surfaces like water, snow, or even sidewalks. That reflection can hit your eyes from behind the lenses. Some high-quality glasses add an extra coating on the back of the lens to block this bounce-back effect.
Important: Dark lenses don’t always mean protection
Just because your lenses are tinted doesn’t mean they block UV. In fact, dark lenses without UV protection can be worse—they make your pupils open wider, which lets in more harmful rays. Always check for a UV protection label, not just the lens color.
Types of UV-Protective Lenses
UV protection comes in many forms—not just sunglasses. Here are the main types of lenses that help block harmful rays:
Clear Prescription Lenses with UV Protection
These lenses look just like regular glasses but have an invisible coating that blocks UV. They’re perfect if you don’t always wear sunglasses but still want your eyes protected—especially indoors near windows or outside on cloudy days.
Polarized Sunglasses
Polarized lenses cut down glare from reflective surfaces like roads and water. Many also include UV protection, making them great for driving, outdoor sports, or relaxing in the sun. Just be sure they say “100% UV protection” on the label—polarized and UV are not the same thing.
Want to learn more? Check out our Practical Guide to Polarized Sunglasses for a deeper look at how they work and when they’re most useful.
Photochromic Lenses
These smart lenses automatically darken in sunlight and return to clear indoors. Most modern versions offer full UV protection in both modes. They’re a convenient option if you want one pair of glasses that works everywhere.
Want to learn more? Check out our blog post: Photochromic Progressive Lenses — All-Day, All-Distance Vision in One Pair.
Do Regular Glasses Protect from UV Rays?
The short answer: Not always. Just because you're wearing glasses doesn’t mean your eyes are protected from UV rays.
Older lenses may offer little to no protection
If your glasses were made years ago—or bought without any special features—they may not block UV at all. Many older plastic lenses don’t stop UV rays unless a special coating was added.
Some modern lenses block UV by default
Many newer lenses, especially those made from materials like polycarbonate or Trivex, naturally block 100% of UV rays. Some optical brands also include UV protection as a standard feature, even on clear lenses.
Not sure if your glasses protect you? Ask your optician
If you're unsure whether your lenses offer UV protection, the easiest and most reliable way to find out is to ask your optician. They can check the lenses and recommend the right upgrade if needed.
UV damage adds up over time. So if you’re not sure whether your current lenses are doing their job, it might be time to invest in a new pair that offers full protection.
Choosing the Right UV Protection for Your Lifestyle
Not everyone needs the same kind of UV protection. The best lenses for you depend on how and where you spend your time.
For everyday wear
If you wear glasses most of the day—at work, commuting, or running errands—consider clear prescription lenses with built-in UV protection. They look just like regular glasses but keep your eyes safe from hidden UV, even on cloudy days or indoors near windows.
For driving
Driving exposes your eyes to UV rays from both sunlight and reflected glare off the road. Polarized sunglasses with UV protection are ideal here—they reduce harsh reflections and help you see more clearly, especially in bright or wet conditions.
For outdoor activities
If you spend a lot of time hiking, skiing, fishing, or working outside, you need lenses that offer both UV blocking and full coverage. Photochromic lenses that adapt to sunlight are a great all-in-one choice, especially if you move between indoor and outdoor environments. Polarized sunglasses are another excellent option—they reduce glare from water, snow, and pavement while providing full UV protection.
For digital screen users
Even though screens don’t give off UV rays, many people choose lenses that combine UV protection with blue light filtering—especially for long workdays or evening device use. Just make sure the lenses are clearly marked for both.
Fit matters
No matter what type of lenses you choose, make sure the frames fit well. Gaps around the edges can let UV rays sneak in from the sides. A proper fit helps you get the most out of your protection.
Care and Longevity of UV-Coated Glasses
UV-protective lenses work hard to keep your eyes safe—but they need a little care to keep doing their job over time.
Handle your lenses with care
Even though UV coatings are durable, they can wear down if scratched or cleaned with the wrong materials. Avoid using your shirt, tissues, or paper towels—they can leave fine scratches. Instead, always use a clean microfiber cloth and a lens-safe cleaning spray.
Stay away from harsh cleaners
Household cleaners that contain ammonia or strong chemicals can damage lens coatings, including UV protection layers. Stick to solutions made specifically for eyewear. If you're ever unsure, just ask us—we’ll point you to safe options.
Store them properly
When not wearing your glasses, keep them in a hard case. Leaving them in a hot car, tossing them in a bag, or placing them lens-down on hard surfaces can all shorten their lifespan.
Watch for signs of wear
If your lenses start to look cloudy, scratched, or just not as clear as before, it might be time for a replacement. UV protection can weaken with damage—better to replace them than risk your eye health.
With the right care, high-quality UV lenses can protect your eyes for years.
Frequently Asked Questions
Are all polarized lenses UV-protective?
Most polarized lenses today do include UV protection, especially when purchased from trusted optical retailers. However, polarization and UV protection are two separate features, so it’s still important to confirm. Always look for labels that say “100% UV protection” or “UV400” to be sure your eyes are fully protected.
How often should I replace UV-protective lenses?
It depends on how well they’re cared for. If your lenses are scratched, cloudy, or several years old, it might be time for a new pair. UV coatings can wear down over time, especially with frequent cleaning or heavy use.
Can blue-light lenses protect from UV rays too?
Not necessarily. Blue-light filters are designed to block a different part of the light spectrum—not UV rays. Some lenses offer both, but they’re not the same. If UV protection is your priority, make sure the lenses are clearly labeled for it.
Ready to Shield Your Eyes?
If you’re not sure your current glasses offer enough protection, or you’re thinking about upgrading, our team at Chinook Optical is here to help.
We’ll guide you through your options, explain what UV protection really means, and help you find lenses that match your lifestyle and vision needs. Whether you're looking for clear lenses with UV protection or a reliable pair of sunglasses, we’ll help you find the right solution to keep your eyes protected throughout the year.