There are both different degrees of blindness as well as different kinds of blindness. There is physical blindness in which the eyes don’t work well or not at all. There is also a blindness we can choose, as when we live in denial of what is going on around us, or when we refuse to believe truths that others tell us. There is also a spiritual blindness in which either willingly or for other reasons, we either cannot or will not see the spiritual reality which is right in front of us. Jesus accuses the Pharisees of being spiritually blind. However, their blindness cannot serve as an excuse for their wrong behavior, for their blindness is willful and chosen. Spiritual blindness is frequently discussed in Orthodox literature. For example from the desert fathers we read:

Getting a beast of burden to turn the mill wheel requires covering their eyes so that they cannot see that they are walking in circles. If they are allowed to see they will quickly stop walking. The desert fathers, as noted above, thought the devil tries the same trick on us – by spiritually blinding us, the devil can trick us into doing his will.  This is why clear vision is so important to the spiritual life. Unlike beasts of burden at the mill wheel, we humans can only be blinded by the devil if we allow it to happen. If we choose to see what is going on in our thoughts or in the world, both the good and bad, then we know the truth, and the truth makes us free (John 8:32).

But it is not only Satan who tries to blind us. We can cause spiritual blindness ourselves by allowing our passions to take control of our lives.

Whatever prevents us from facing reality is a threat to our spiritual well-being. If we only accept ‘facts’ that we agree with, then we are choosing to blind ourselves to the reality in which we live. If our passions govern how we react to things, we are allowing our passions to blind us to reality because in our passions, we tend to see and hear only what we want to see and hear…

 – Fraternalized Meditations blog