I usually can tell when I enter SP because everything turns black then white and/or I hear a loud ringing that I can't quite tell what it is and my radio sounds garbled. But something else has been happening lately: I lay down for about 10-20 minutes and while my eyes are closed I feel like I'm spinning around in every direction but that's it, when I open my eyes everything's normal except sometimes a bit out of focus. Is this SP? Also if I open my eyes I can move around and stuff...