VLT - Visible Light Transmission. This is a percentage based on the amount of light that will come through to your eyes. Generally, a higher percent VLT makes it easier to see through the lens in low-light conditions. A lower VLT percentage will be more useful during very bright conditions, and when dealing with harsh reflective glare from the sun. VLT % may vary between spherical and cylindrical lens shapes.
S1 (Low Light) - 43-80% VLT
S2 (Medium Light) - 18-43% VLT
S3 & S4 (Bright Light) - 0-18% VLT
Light Sensitive (S1-3, S2-3, S2-4): These lenses engage photochromic technology and adapt automatically to sunlight intensity. Within seconds the lens will darken when the brightness gets stronger or lighten when the sunlight gets weaker. The photochromic pigments are combined with a SCOTT Amplifier-based tint, which provides a super contrast even in low light conditions.
Illuminator (S1): Developed to let almost 90% of yellow and orange wave lengths pass the lens and emphasize the brightness perception, while shutting out the bad light to maintain a very good level of contrast and depth of perception.
Enhancer (S2): Combined with AMPLIFIER technology these enhance contrast in overcast and mixed conditions. Great for a variety of days.
Solar Blocker (S3): Offers excellent clarity by filtering out the harmful blue light during bright sunny days while keeping the natural contrasts, resulting in decreased dazzling effects and reduced fatigue coming from the high intensity ambient brightness.
Natural Light (S2-3): Enhance clarity and contrast while maintaining neutral lens tints.
Amplifier: utilizes a unique light transmission curve to optimize the transmission of key light waves that are most important to the human eye, so you can see more in every condition.