Sunglass Tint & UV Category Finder
Enter a lens's light-transmission percentage and see its filter category, how dark it really is, and where it's safe to wear — including behind the wheel.
Filter category
Category 3 — Dark tint
Dark tint (8–18% light transmission). The most common strength for bright sun.
Ideal for strong sunshine, beaches, water, and snow. Fine for daytime driving; never for night driving.
Category describes darkness only. Any sunglass should still block UV (look for UV400 or 100% UVA/UVB) — a dark lens without UV filtering is worse than none, because it widens your pupils.
Darkness, category, and the UV that actually matters
Sunglasses are graded by how much light they let through, not by how cool they look. That single number, the visible-light transmission, sorts a lens into one of five categories from clear to glacier-dark, and those categories carry real rules — most importantly, that the darkest ones aren't legal to drive in. This tool translates a VLT into its category and spells out the daytime and night-time driving implications.
The catch worth repeating: tint and UV protection are independent. A category tells you about glare and comfort, never about ultraviolet. Always pair the right darkness for your conditions with a lens marked UV400 or 100% UVA/UVB — a dark lens with no UV filter opens your pupils and lets more damaging light in than bare eyes would.
Frequently Asked Questions
What is VLT and where do I find it?
Visible-light transmission (VLT) is the percentage of visible light a lens lets through — 100% is clear, a few percent is very dark. It's often printed on sunglass packaging or the lens itself, sometimes as a filter category number. Lower VLT means a darker lens.
What do the sunglass categories 0 to 4 mean?
Under EN ISO 12312-1, lenses are graded by VLT: category 0 (80–100%, clear to very light), 1 (43–80%, light), 2 (18–43%, medium), 3 (8–18%, dark — the common sunglass strength), and 4 (3–8%, very dark, for glaciers and high altitude). Higher category means darker.
Which categories are safe for driving?
Categories 0 to 3 are fine for daytime driving. Category 4 is too dark for driving at any time and is meant for extreme glare like mountaineering. For night driving, only category 0 (essentially clear) is appropriate — no tinted lens should be worn to drive after dark.
Does a darker lens mean more UV protection?
No — and this is the important part. Tint darkness and UV filtering are separate. A lens of any category should still block UV (look for 'UV400' or '100% UVA/UVB'). A dark lens without UV protection is actually worse than none, because it makes your pupils open wider and let more UV into the eye.
What tint should I choose for everyday use?
For general bright-day wear, category 2 or 3 covers most people — 3 for strong sun, beaches, snow, and water; 2 for variable conditions. Drivers who want a lighter lens for overcast spells might prefer category 1 or 2. Whatever the tint, confirm it carries full UV protection.
Educational guide to lens categories. Always check a sunglass carries full UV protection, and follow local law on tinted lenses and driving.