John 9:40 Some Pharisees overheard him and said, “Does that mean you’re calling us blind?”
Some people who boast of having a clear vision are often spiritually blind. The Pharisees were shocked that Jesus thought they were spiritually blind. Jesus answered that only blindness (stubbornness and stupidity) could excuse their behaviour. It is to those who openly recognise how sin has truly blinded them that Jesus gives spiritual understanding and insight.
BEWARE: complacency also leads to spiritual blindness. http://ow.ly/d5t1g