At such a young age, either type of hay is fine.At 3 weeks, they'll start to nibble on pellets and drink water, so youmight wish to have some available.
At around 10 days old, they should open their eyes. If they haven't, itcould indicate an eye infection and if you use a cotton ball with warmwater to soften the crust on the eyelid and carefully separate theeyelids, it would help them. I've heard of some people using Visine ifthe edges of the eyelid look red. If you do have one that does havethis problem, repeat this process for a couple of days.
-Carolyn