My eyelid is swollen and itchy for the second time this month? both times after the beach? HELP?

My only thought is maybe the salt water is irritating your eyes. Try taking a shower either at the beach or right away when you get home.... or -at the very least- bringing a bottle of fresh water with you and rinsing out your eyes before you leave the beach. Not sure if that is it, but it's worth a try!