I don't think you actually see anything after the first few seconds, as all the blood inside your head will be draining out very rapidly. If you've ever had that type of fainting fit that happens when you stand up too suddenly, you'll know that vision is the first thing to go - you feel a sharp dragging pain behind your eyeballs then the brown mist descends. Then your balance and orientation goes. You probably get the most godawful headache as your cranial blood vessels suddenly clamp - maybe your sinuses start hurting as well. But, luckily, the brain is shutting down rapidly by that time, so the pain doesn't last for long - your 'centre of conciousness' is shrinking fast, like a deflating baloon. All the noises of the crowd fade away. Finally, you are left in the dark, wondering "Wha....???"