“has eyes in his head.” This phrase is idiomatic for the person being able to see where he is going.
“one event happens.” This one event is death. The Hebrew text emphasizes this by the figure of speech polyptoton, in this case juxtaposing a noun and verb with the same root. It is hard to reproduce clearly in English, but it might roughly be translated, “one happening happens to them,” or “one occurrence occurs to them.”