I was walking up a stairwell when I saw a mist in front of me, my clothes became damp and my face and eyes were covered in spray. When I got further up the stairs a pupil was stood there with the canister in her hands. I said have you just sprayed me with that, she said 'she didn't do it'. I asked her to hand the can over but she refused. I reported it to my manager and a call out to security was done to have her picked up because she ran off. She told everyone she didn't do it but was sent home. I completed an incident report and a IRIS consequence. I went to the science department and had my eyes rinsed but the following day my eyes were stuck together and itchy with blurred vision. I went to my GP who completed some eye dye chemical tests on me for Cornea damage - none found. I am off sick now but I am frightened to return. GP offered me a 2 week sick note but I have declined at this time. I have notified the Principal of the incident and I wish to be moved to another post. My GP stated I should report it to the Police. What would you do?