Kitten eye gunk?

Our kittens are 3 weeks old and have had their eyes open for 2 weeks. Last week one of them had one eye almost completely closed with some hard gunk, I wiped it a bit with water and after a few days it was fine. Then a few days ago another kitten had the same think, and it seems to be getting better now. Is there anything special I should do when this happens, or just gently wipe it? They don't look infected or pussy, just kind of sealed closed. Is it normal for this to happen with kittens?

BTW the little runt is doing great now. They are all growing and getting more active. I need to take some new pics.

Yes, that is normal. As long as there is no pus or their nose isn't running-if so, do take to a vet for some ointment. I make a mixture of tearless kitten shampoo and warm water and wet a cottonball and gently wipe their eyes 2-3 times a day and after a few days it will clear up. ( :

Thanks Good to know it's normal.