i assume you wear gogles, do you have a prescription for glasses? was your blurred vision on a sunny day? do you ski south facing slopes all day? the reason i ask is 2 things come to mind.
1. if it is sunny and you dont wear gogles at all or cheap gogles or sun glasses the sun could be reflecting into your eyes, if you ski south facing you are usually in the direct path of the sun for most of the day.
2. possible dehydration, not enough sugar, electrolytes etc... If i am chasing pow all day I do not stop, 25-30 runs in a row in knee deep will kick anyones ass, i just buck up and keep going. I try to eat a good breakfast early and snack on the way up. if i do not stay fueled up AND have a good breakfast, when i hit the car at the end of the day i am dizzy and nautious and shit spins, i have to sit there for about 1/2 hour befor i can drive home.
there are other posibilitys, hope this helps