Superman.
This thread reminds me of a comparison that came to mind recently. Back on the 1950's Superman TV Show, I remember an episode in which Clark Kent took his glasses off near Lois Lane and some others from the 'Daily Planet' who knew him well. Yet, none of them realized he was Superman. Talk about being blind!
In real life, the same with those who aren't convinced Barack Hussein Obama is a Muslim despite overwhelming evidence! What more do people need to see to be convinced!