Prescription lens tint categories explained

Shades of grey:

• Cat 0 lenses

  Category 0 lenses are essentially at the “clearest” end of the sunglass tint scale.

  They typically have a visible light transmission (VLT) of around 80–100%, which means they let almost all available light through. This makes them ideal for:

  • Safety glasses (e.g., industrial, laboratory, or construction use)

  • Low-light sports like evening football, cycling at dawn/dusk, or indoor court sports

  • Overcast or foggy weather where you still want eye protection but don’t want to reduce brightness

  • Fashion or everyday eyewear when you want a barely noticeable tint

  They don’t offer significant glare reduction, so they’re not suited for bright, sunny conditions — their main job is impact protection or improving contrast without darkening your view.

• Cat 1 lenses

  Category 1 lenses sit just above Cat 0 in darkness.

  They usually have a visible light transmission (VLT) of about 43–80%, meaning they let in quite a lot of light but still cut a bit more glare than Cat 0.

  In sport, they’re often:

  • Yellow, amber, or light orange (sometimes pale rose)

  • Designed for low light or overcast conditions

  • Used to enhance contrast and depth perception, which is especially useful when distinguishing textures in snow, targets, or road surfaces

  Common applications:

  • Skiing or snowboarding in cloudy or flat-light conditions

  • Shooting sports to make targets “pop” against the background

  • Cycling at dawn, dusk, or in wooded areas

  • Golf in hazy weather to better see contours on the green

  They’re not dark enough for bright sun — that’s when you’d move to Cat 2 or 3.

• Cat 2 lenses

  Category 2 lenses are a kind of “all-rounder” for sports eyewear.

  They usually have a visible light transmission (VLT) of about 18–43%, so they let in less light than Cat 1 but aren’t as dark as Cat 3.

  Key traits:

  • Common colours: amber, brown, or copper tints

  • Performance: enhance contrast while still cutting a fair amount of glare

  • Best for: variable light conditions — from bright overcast to moderately sunny days

  • Sports uses:

    • Skiing in mixed sun/cloud conditions

    • Cycling in changing weather

    • Shooting for contrast and glare balance

    • Some equestrian and water sports

  They’re versatile, but in very bright sunlight you’d still get better protection from a Cat 3 lens.

• Cat 3 lenses

  Category 3 lenses are what most people think of as “normal” dark sunglasses.

  They have a visible light transmission (VLT) of about 8–18%, meaning they block over 80% of bright light while still giving good visibility.

  Key traits:

  • Colours: usually grey, brown, or green

  • Protection: strong glare reduction + full UV protection

  • Best for: bright, sunny conditions

  • Sports uses:

    • Cricket (especially fielding)

    • Fishing (often polarised to cut water glare)

    • Golf (reading greens in sunlight)

    • Sailing and other water sports

    • Tennis in full sun

    • Skiing in clear, bright weather

  They’re too dark for low light or overcast days, but perfect for summer midday sun or high-glare environments like snow and water.

• Cat 4 lenses

  Cat 4 – Lenses are much more specialised and are used for extreme applications. They allow only a small percentage of light to pass through the lens — approximately 5 to 8% VLT. The lenses are used for medical conditions such as photophobia or after eye surgery. Other extreme uses include high-altitude mountaineering and expeditions in the Arctic.