My baby girl just opened her eyes the day she came to the world. Now she is 6 years old and with good health. I think you needn't worry about this. Babies will do this when it is time to do. Don't force it to happen. If you met any difficulties, you can consult your pediatrician first.
Hum, naturally it will take 27-28 weeks for the newborns to open their eyes. They often sleep a lot. Don't worry too much because these are common phenomenon. Let nature take its course. And their little eyes appear to be swollen at first, but they will come around slowly. If you have any questions, you can call your doctor and tell them your concern.