yeah .............. it happens. Not to me, but I see the topic pop up on the forums every now and then (you could do a search on "blind" or "can't see" and see what comes up!).
The advice usually given is to ORDER yourself some sight (like a hamburger in a drive-thru? ha ha! No, not like that.) ORDER IT, like a command. "SIGHT NOW!" or something like that. Apparently, it works.
Lately, I've been having these very short projections where I (think) I am just above my body but I am having a hard time seeing so I consciously lift my "hand" up and rub my eyes and then I can sort of see but I become too aware and then my awareness flips back and forth from my sleeping body and ultimately I wake up. Does anyone else ever have this problem? Do you also just rub your eyes with your "astral" hand? Sometimes they are so short I cant tell if it's a dream or a projection.