And the disciples came, and said unto him, Why speakest thou unto them in parables? He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given.
Matthew 13:10-11 KJV
Blindness in the spirit is not limited to unseeing eyes. it is an alteration or deviation of your perception from actual reality.
Spiritual blindness is the strategy of the devil to thwart dominion from the Saints.