For the case 998/2, here's what happens:
Say A and B have blue eyes. Before the vistor's statement, this is what A might have been thinking:
"This dude B has very pretty blue eyes. I wonder if I have such pretty eyes."
B's thoughts are completely symmetric.
Now what can change after visitor's statement? Here are A's thought just after the statement was made:
"Do I have blue eyes? Let's see. Say I don't. Then, I know that B is the only guy with blue eyes. Clearly he now knows that since that idiot visitor made it known that there is someone with blue eyes. So he should kill himself tomorrow. That would be so awesome to watch
."
B's thoughts are entirely symmetric. So both A and B wait for the ritualistic suicide. But the fateful moment comes and no one commits suicide. Here's what A's thinking now:
"
! Why isn't B dead? Surely because I do have blue eyes and he was waiting thinking that I might die today. Crap! Now I know that I have blue eyes. I'm shooting myself."
B thinks the same and they both immediately commit suicide.
Can you extend the argument to the case 900/100?