Suggest Treatment For Swelling In The Eye

my son is 2.8 yrs, and has swollen eye, left one. yday afternoon, after his sleep when he woke up, I saw his eye swollen,upper lid.i applied coco oil.he woke up today morning with much swollen eye.i felt it was bit reddish.no discharge, he does not rub.i applied neosprin. but it has reduced only little.i fear torw morning.he is not allergic to any foods, and this is first time