I knew that I felt like fainting today during the mile run. My hearing started fading away and my vision got really bad.
Everything turned red and blury. I was also very light headed.
So then my teacher says something like this "If you're not in line to turn in your sticks, you will get a zero for your mile".
So, I am like damn! Then it got worse and worse and I was about to collapse. So then I am like **** this I'm leaving. I ditched class and was walking to the closest water fountain. During my drunk walk, I was getting worse by the second and ended up pretty much blind and deaf.
I don't know how I made it, but I was there... WATER! Took a couple of sips and then everthing started to clear up. My vision and hearing was back to normal. I was so happy right after and walked back to my teacher all wet. I explained everything to her and she said I looked paled.
At least I still got the grade 
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This is how my vision looked like... it's not my PE Track btw.
Just looking at it makes me feel sick 
It wasn't exactly like this but similar.