The Flight Deck L is a large fit, frameless goggle that takes its inspiration from the helmet visors of fighter pilots. The resulting, unique look provides a massive field of vision. In addition to the wide view the Flight Deck L is complimented by a whole host of Oakley\'s top end tech features.Lens: Prizm Sapphire Iridium (covers a range of light conditions, from overcast to bright)VLT: 13% (CAT 3)Size: LargeLens Shape: ToricLensPrizm Sapphire Iridium is suited for variable to sunny conditions; the Iridium coating reduces glare from sunlight reflecting off the snow, whilst the rose tint increases definition in flatter light. Prizm technology blocks specific wavelengths of light whilst boosting others to provide maximum contrast and enhanced visibility. This greater clarity results in reduced reaction times and increased performance over a wide range of light conditions.Visual Light Transmission, VLT, refers to the amount of light that penetrates a lens. A low percentage means less light passes through and a higher percentage lets an increased amount of light through. A lens with a lower VLT rating is better for bright conditions; where as one with a higher VLT is more suited for overcast and snowy days.