Eye lid wrinkle from mask causing temp blindness?

I took a nap today and when I woke up my (old respironics) mask was in an odd position smashed face down on my pillow. I could not see out of the top half of my right eye! I freaked out thinking I had gone blind. I had an aunt that went blind and it happened within a matter of two hours. I looked at my eyes in the mirror and I could clearly tell that my right eyelid was covering my eye lower than my left. I had formed a wrinkle on my eyelid. I thought if I laid down on my back with my eyes shut that it would straighten back out. Sure enough, that worked. Has this happened to anyone? I just thought it was really bizarre.