VLT stands for Visible Light Transmission. The higher the percentage, the more light passes through the lens to your eyes. The lower the percentage, the lower the amount of light passing through the lens. On top of style, color, and performance, choosing your VLT is another way to customize your glasses or goggles. You can tailor your new lenses to the lighting conditions in which you'll most often be using them.

Keep reading for everything you need to know about VLT!

In This Post:

Lens Tints
VLT Categories
Category 4 (S4)
Category 3 (S3)
Category 2 (S2)
Category 1 (S1)
Category 0 (S0)
Variable VLTs
Why VLT Matters
Prescription Glasses and Goggles!

Lens Tints

Let's look at which VLT percentages match the type of tint you need. For snow goggles, check out our blog How to Choose a Snow Goggle Lens Color.

VLT Categories

VLT ranges are classified by categories. These categories—often referred to as just "Cat"—range from 0 to 4, with 0 being the lightest and 4 being the darkest. Snow goggle categories often use an S instead of a C, such as with S0-S4.

Now that you know the category ranges, let's get into what to expect from each category and what conditions they work best for.

Category 4 (S4)

This VLT ranges from 3-8%. Lenses with this tint density are for excessively bright conditions and are less common overall. Cat 4 lenses are usually unsafe for lifestyle activities, driving, or operating any kind of machinery since they cut so much light transmission. This range is usually reserved for high-altitude mountaineering or shop welding.

Category 3 (S3)

This VLT ranges from 10-18%. Lenses with this tint density are for variable light conditions, such as sunny days with clouds. Most sunglass lenses have Cat 3 lenses. The lower end of this range usually includes lenses with mirror coatings. Cat 3 lenses are a great option for driving, water, or snow activities. Popular tints that fall within this range are grey or copper.

Category 2 (S2)


This VLT ranges from 20-43%. Cat 2 lenses are best for medium to low-light conditions. These provide the perfect amount of brightness protection for an average amount of sunlight and a wide range of activities. If you are not light-sensitive, Cat 2 lenses are also great for everyday use.

Category 1 (S1)

This VLT range goes from about 43-80% and is for dusk or other low-light conditions (but not night!) and is especially useful on cloudy days. Colors with light tints are usually yellow, amber, or rose and are chosen for their high color contrast depictions. Good for shooting, cycling, and golf.

Category 0 (S0)

This VLT ranges from 80-100% and categorizes lenses with little to no tint. Cat 0 eyewear is usually for indoor or night activities. Even clear lenses can fall in the 80% range! Eyewear with this VLT usually includes eyeglasses, fashion eyewear, safety glasses, or lenses for night snowboarding or cycling.

Variable VLTs

Photochromatic lenses have varying VLTs. These lenses automatically transition from a clear or light tint to dark with UV exposure. Photochromic lenses have a wide range of light transmission that can span from 15-50%, and are versatile enough to work well in just about any condition. The term 'transitions' has become synonymous with photochromic lenses, but it's actually a name brand and the leading option in terms of quality. Learn more in our blog Transition Lenses: What You Need to Know.

Why VLT Matters

Aside from being necessary for your overall comfort, choosing eyewear with the right VLT can enhance your experience based on your environment. Not only does it help prevent straining or irritation, proper VLT can also be a safety precaution. The next time you shop for a new pair of goggles or sunglasses, understanding your VLT will help you make the best decision for your adventures.

Stay comfortable and confident with a VLT that best suits your lifestyle!

Prescription Glasses & Goggles at SportRx

Need prescription glasses or goggles? Done. When you shop with us, you’ll find video guides and tooltips throughout the build process as you customize the perfect pair. An answer to all your questions is at your fingertips, and if you want to chat with an expert, contact us. We’ll put you in touch with one of our friendly in-house opticians who can help you build your prescription glasses or goggles.

Ditch risky online shopping with the See Better Guarantee. Try your eyewear for 45 days. If you’re not satisfied, send them back. Get a full refund, exchange, or credit towards a better pair. And return shipping? Covered. Get your pair of prescription glasses or goggles at SportRx today!

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