My son hit the corn of is eye yesterday and it swelled up abit and we iced it. this morning his eye and eyelids are very swollen and the eye is partly closed. should we worry?

Yes: Swelling around the eyes, meaning in the upper and lower eyelids, after trauma that broke the skin, may be due to cellulitis. Cellulitis around the eye is an infection that needs evaluation and antibiotics. If it turns out that after his doctor's evaluation the assessment is not cellulitis, that would be good. Since one cannot tell without an exam, a trip to the doctor is generally needed.