I went through a period of time when I couldn't recognize lows. My husband and mom could tell before I could. They commented about the "look in my eyes" but never mentioned puffiness.
When I have a hard low my eyes jerk. Maybe pre-convulsions? Who knows. It complicates the recovery, because I can't visually focus on anything (juice box, etc) or make my way to a chair because everything in sight is jumping around.
I've always wanted to see some tv special on exactly how the body responds to low blood sugars. After a hard low I get bone cold and can't warm up in less I stand in a hot shower. Possibly my body in shock?