Rinse with sterilized water (boiled and cooled down). Lubricate eye with synthetic tears (eyedrops called Tears Naturale). If eye remains sensitive and red or swollen shut or starts emitting anything other than tears, you may need anti-allergy eyedrops or in the event of an infection, antibiotic drops. You will probably need the advice of a pharmacist or doctor to determine which one it is you are dealing with. Do not delay, get it attended to, if it is still in the condition you describe so many hours after the event it may well get worse rather than better if left unattended. Hope this helps! I am not a doctor or medic and accept no responsibility for this advice!!