A polarized lens improves vision and reduces eyestrain in bright conditions by reducing glare from reflective surfaces. It also blocks UVA and UVB rays. Polarized lenses are usually brown or grey (suitable for bright conditions) or greygreen (better for flat-light conditions). Recommended for running.
Visible light transmission (VLT)
VLT refers to the amount of visible light that passes through a lens; the lower the VLT (expressed as a percentage), the darker the tint.
Another measure of a lens’s tint. Category 0 refers to a clear or lightly tinted lens with 80 to 100 per cent VLT, suitable for lifestyle use or at night, category 4 to a lens with 3 to 18 per cent VLT, suitable for strong sunlight.