dragon nfx snow goggle replacement lens (lumalens silver ion) dragon alliance the nfx lens is spherical for themaximum range of vision with zero distortion. all dragon lenses provide 100% uv protection and exceed ansi z87. 1 impact test standards. the dual-lens design and dragon's armored venting reduce fogging, and the tough polycarbonate construction is tough to scratch or break. a polarized version is available to cut out glare.