The Savor Big HD goggles are packed with technology - delivered in a big, bold, and beautifully simple package. There's Fusion Double Lens for a field of vision up to 20% larger with no reflections or fogging. HD Lens Technology helps to massively improve contrast in all conditions. They're also Over The Glasses compatible meaning they fit comfortable over prescription glasses if needed. Green HD Lens covers Categories 3 & 2, Sun to mostly cloudy. Blue HD Lens covers Categories 2 & 1, Partly cloudy to flat light.