Is the lifespan of someone with ambloyopia different from that of a normal person?

No. Unless i suppose someone is more prone to accidents because they only have one good eye and therefore poor stereopsis.
No. Amblyopia is usually caused by crossed or misfocused eyes. Sometimes of course, the extreme misfocus or crossing is a symptom of a much more serious underlying problem but in general, amblyopia should have no negative influence on lifespan.