VLT allows athletes to fine tune their vision by selecting a lens based on how light or dark it is.
VLT is Visible Light Transmission. This refers to the amount of visible light that is let in through a pair of lenses.
Visible Light Transmission in sunglasses and goggles is represented by a percentage. Dark lenses have a lower VLT %, meaning less light passes through. Lighter lenses have a higher VLT percentage because they let more light pass to your eyes.
Our wide range of VLT offerings allows athletes to select the lens that's best suited to their preference. Prefer a dark lens for full-sun days? Go low VLT. Prefer to have a bit of coverage even on overcast days? Go high VLT. Want something that adapts? Photochromic lenses adjust their VLT in response to the sun's conditions.
VLT categories are a standardized system recognized to help athletes quickly identify and categorize a lens' tint. Prefer lighter tints? Look for Category 1-2. Looking for a dark tint for full-sun days and extreme conditions? Go for 3 or 4.
| Category | VLT | Description |
|---|---|---|
| Category 4 (S4) | 3% to 8% | Very dark tint, allows only a small amount of light to reach the eyes. Designed for extremely bright conditions, such as snow, sand, and mountain top expeditions. |
| Category 3 (S3) | 8% to 18% | Dark tint, ideal for full-sun days on the water or in open fields. |
| Category 2 (S2) | 18% to 43% | Medium tint, versatile, covering both medium cloud coverage days and sunny days as well. |
| Category 1 (S1) | 43% to 80% | Light tint, perfect for overcast, dimming light, or when you prefer a light tint on sunny days. |
| Category 0 (S0) | 80% to 100% | Very little or no tint, effectively translucent. |
Most SPEK lenses and frames are designed to be interchanged, enabling runners, cyclists, skiers, and snowboarders to finely tune their vision by choosing the right lens for the effort at hand.