Sunglass lens categories – what do they mean?

Following the last news post about polarised lenses, along a similar theme we thought it worthwhile explaining what the different sunglass lens categories mean. The category number equates to a percentage of the VLT (Visible Light Transmission) that is, how much light the lens lets through. The higher the VLT the lighter the lens, conversely the lower the VLT the darker the tint will be, blocking more light coming through to the eye, as follows:sunglass lens category table

  • Category 0: 80-100% VLT
  • Category 1: 43-80% VLT
  • Category 2: 18-43% VLT
  • Category 3: 8-18% VLT
  • Category 4: 3-8% VLT

The following is a general guide to the categories that apply to different lens colours. This has to be a general guide as the VLT can cover quite a wide a spectrum such as Category 1 which is 43-80%. Some lens colours are right on the “border” e.g. a yellow lens can have 78% VLT which is on the border between Category 0 and Category 1.

  • Category 0 – Clear, Light Yellow, Pale Orange
  • Category 1 – Yellow, Orange, Rose & Vermilion
  • Category 2 – Purple, Red, Amber & Light brown
  • Category 3 – ‘Standard’ Grey & Brown
  • Category 4 – Dark Grey & Dark Brown

Virtually all the grey and brown lens sunglasses we sell are Category 3 and suitable for use in strong sun conditions. See our range of leisure sunglasses.

Category 4 sunglasses are a specialist lens for intense sunlight/high glare conditions and they are clearly denoted in the product description. They also appeal to people that have very light-sensitive eyes (called photophobia). It’s important to note that a category 4 lens must not be used for driving as they are too dark and therefore potentially dangerous. It’s also worth pointing out that tint has nothing to do with blocking UVR. You can buy cheap sunglasses with a category 3 lens but without UV filters it can let in very harmful levels of UVR, damaging the eye. This is why good quality sunglasses have UV coatings applied to the lenses. Some lens materials do naturally block UV such as glass and polycarbonate.