No, it shouldn't take a week. Usually both eyes are open within a day of each other. I have some that do what your describing. They are "Silky/curlies" and there must be some imune deficiency or fatal gene combination in them as the one that do this grow very slowly and rarely if ever reach adult hood.
If all of your babies are doing this you may want to go ahead and start with some fresh stock for your breeders, you may have a imune deficient or fatal gene combination happening.
Good luck! Let me know if they go ahead and come around, it would be interesting to know.