What can dog owners do to help a dog who just turned blind?

Thank you very much! Yeah, we noticed she was a lot more confused after we rearranged everything after Christmas (because we no longer had the tree up), which is when we believe her vision started to fade. And, yes, the basement door is a lifesaver; the basement stairs were the first hazard we discovered because she tripped all the way down the stairs when no one was looking — thankfully, she was fine, just freaked out, but still.