I have been looking for help with these symptoms and trying to figure out what is wrong, so hopefully someone can point me in the right direction. When I lay on my stomach and prop my head up (lying in the prone position) I start to get light headed, as if the blood flow is being cut off. I get the same feeling if I am standing and look straight up. It feels as if I would black-out if I continued to stay in that position. I have not noticed any vision problems when it happens but my hearing sounds as if my head is in a glass dome (that is the best way I can describe it). I noticed the problem after I had my daughter 2 years ago and lately it seems to have gotten worse. My blood pressure is normal, I workout 4-5 days a week, and except for being slightly overweight I have no health problems. Any help will be greatly appreciated!