I have not heard of babies wth it, but I worked for an ophthalmologist for years and we had patients that had that. I also have a niece who was born without muscles in her eyelids to hold them open. She has had several surgeries, the last one was to put synthetic muscle in her eyelids- she was around 7 yr old, now 11 yrs old.
All I can say is, if you are not sure about this procedure get a second opinion. If he is going to a pediatric ophth. at Midwest Eye Inst., that is probably the best place. They know what they are doing. Are you sure it is 8 hours? I can't imagine that it would take that long unless they are doing muscle grafts, or something more extensive than the stitches or staples in his eyebrows.
A child has to be able to see his world in order to learn and develop normally. You are doing the right thing by getting this fixed, but make sure you have all the information you need. Then, put it in God's hands, trust that he will take care of your baby.