If its swollen shut, it has to be a bother to him. My advice would be to take him to the pediatrician b/c it COULD be something that needs to be treated. Plus, it never hurts to be safe, and with his eyes being in close proximity to his brain, and infection in that area is always important to treat ASAP. Not to worry you, but w/ my experience as a nurse in pediatrics, I have seen some cases of eye infections that get pretty ugly left untreated, plus his age, he is probably going to have his hands in it, which is a preceptor for spreading it to the other eye, if it were to be an infection. It could be something more simplistic though, such as allergies or such, I'm not a MD and I haven't seen it. I would go with your instinct, b/c mommy normally does know "best." I'm a firm believer! ;) Good luck and I hope he recovers well. Have a good week.