What Causes Crystal Vision On Corner Of Eyes After Playing Soccer?

hi my names Kaden. I have a problem when playing soccer on sundays where i frequently get stitches after a short while of sprinting/jogging, sometimes just warming up. Ive tried not eating well before my games and training which doesn't seem to help. Ive also tried drinking alot less water and sometimes hardly any at all for a while before my games. I thought this was actually helping. i would still get small stiches, but i was able to contoll them by just backing off the pass a little. But now that ive been doing this each week, im noticing that about an 1hr after my games i start to get a kind of crystal vision in the corner of my eyes. this turns into a bad headache after about 20mins and ive learnt now to take panadol as soon as i notice it. Was just wondering if any of you could give me some advise on any of this? :)