Snow blindness is a kind of temporary blindness or the vision worse by the reflected sunshine by the snow surface. After you find this disease, you will have to recover well from it in the good environment for at least 5 days. Usually the good treatment period is between 5 and 7 days.
It depends. How long does snow blindness last depends on the length of exposure in sun when you stay in snow. Sometimes, it meed a few hour to recover from snow blindness. But sometimes, it is need a few days. Besides, In very extreme cases, snow blindness can cause blindness permanently.
It's a temporary eye disorder that lasts about 12 to 24 hours. Snow blindness appears when the intense UV rays mirrored the snow into your eyes to burn your cornea. In such case, it's not easy for you to distinguish colors because your eyes would see everything in red. Hence, it normally disappears when you close and rest your eyes for a certain period indoors.