Skiers and snowboarders face extremely bright sunlight, especially when it's reflected off the white snow. That can make it hard to see, and not just because of glare. The blue light waves in sunlight makes it more difficult to distinguish colors. When colors blend together, a skier may not be able to perceive a sharp drop off or dip in the terrain. A NASA-designed filter used in snow goggles helps block up to 95 percent of blue light. The filter makes it easier for people on the slopes to see the different land formations clearly and, as a result, prevent falls and crashes.