Field of view measures how much peripheral vision your goggles provide, typically ranging from about 140 to 210 degrees horizontally. A wider field lets you spot other skiers, terrain changes, and obstacles without turning your head as much — which is especially handy in crowded areas, trees, or steep terrain where quick awareness matters.
Racers and freeriders benefit most from maximum peripheral vision, so they should aim for the upper end of that range. Casual resort skiers probably won't notice a difference of 10–20 degrees, so a mid-range option works just fine.
Two things to watch out for: don't chase the highest number blindly, as very wide lenses can distort your view at the edges, and never sacrifice goggle fit just to get a wider field. A goggle that fits well with a solid seal will always outperform one with a massive view that gaps or fogs up on the mountain.