Not noticing things has nothing to do with your eyes. It's inattentional blindness, which has a very famous example in the "Invisible Gorilla"-experiment.
I wish Akaha would get what's coming to her but this is obviously one of those 'all is forgiven'-manga. And Takaharu is obviously gonna end up with her. At least the character designs are visually pleasing.
I wonder what the people calling this victim blaming would say to me if I went to a bad neighbourhood, at night, while counting a fat stack of bills and got mugged.