The need to visually recognize irregularities in the terrain, such as hummocks or hollows, is necessary for the skier to react appropriately. The state of the art is to use blue attenuator filters or grey filters as sunglasses. But without knowledge of the spectra, e.g., the surface of the slope, it is impossible to choose or develop an optimal filter. We measured the spectra of snow under various conditions. These data served as a base to develop a new kind of filter suitable for skiing. Some physiological evidence is given why this new kind of filter is optimal for skiing. The filters are already used by the German Ski Federation World Cup team (women) in both training and competition.