maximum optical performance - the pxv2 from dragon. the pxv2 combines dragon's groundbreaking panotechâ„¢ lens system with the super-fast swiftlock lens change system. the size is right in the optimal range: slightly smaller than the pxv and slightly larger than the popular nfx2. dragon's panotechâ„¢ lens system features a unique curvature that allows it to wrap around the frame more, for an expanded field of view in a visually appealing design.lumalens® purple ionlumalens® technology provides optimised colour and glare protection through an ionised lens coating. the hard coating is scratch resistant and repels dirt, dust, oil and water.transmittance of visible light: 23 %bonus lens lumalens® amberthe amber lens offers perfect protection in poor visibility. reduces glare, increases contrast and prevents premature eye fatigue in overcast conditions.transmittance of visible light: 54 %