The Visible Light Transmission (VLT) of sunglasses is measured in categories, with the lower numbers representing lighter lenses. You can find the lens category for your selected frames on their product page.
• Category 0 (CAT0) refers to safety glasses that offer impact protection only. They have a mild tint or are completely transparent. Blue-light blocking lenses are included in this category.
• Category 1 (CAT1) glasses are good for overcast light, but not good in bright light.
• Category 2 (CAT2) glasses are suitable for use in moderately bright light and offer decent glare protection.
• Category 3 (CAT3) sunglasses are the most common category and are very effective at blocking out visible light.
• Category 4 (CAT4) sunglasses are brown or grey and minimise glare. They should be avoided when driving.
It is worth noting that all Valley lenses, regardless of category, block 100% of UVA and UVB light.