When I raised a litter of kittens, their eyes did the same thing. Let them open on their own, though. Unless, they look really nasty and gooey, in which case it should be checked out.
My kittens also sneezed. They turned out to be perfectly fine and only sneezed for a couple of days. Had I known at the time how potentially dangerous URI's could be with kittens, though, I would have taken them to the vet to be checked out.
To be safe, I would have the vet take a look. I've heard several people say that when you take a young kitten in, it is best to pack up the entire litter and momma with you...not completely certain myself, so maybe someone else can jump in and tell you for certain.
I'll bet they are precious. You sound like you are doing a wonderful job at helping to raise these kittens! God bless you!