The mouth and eyes demonstrate one spiritual condition, whether good or bad.

Eyes

For God knows that when you eat of it your eyes will be opened, and you will be like God, knowing good and evil.” Gen. 3:5

Make the heart of this people fat, and their ears heavy, and shut their eyes; lest they see with their eyes, and hear with their ears, and understand with their hearts, and turn and be healed.” Is. 6:10

“Hear this, O foolish and senseless people, who have eyes, but see not, who have ears, but hear not. Jer. 5:21

Mouth

But the word is very near you; it is in your mouth and in your heart, so that you can do it. Deut. 30:14

And he touched my mouth, and said: “Behold, this has touched your lips; your guilt is taken away, and your sin forgiven.” Is. 6:7

Thus says the Lord GOD, Behold, I am against the shepherds; and I will require my sheep at their hand, and put a stop to their feeding the sheep; no longer shall the shepherds feed themselves. I will rescue my sheep from their mouths, that they may not be food for them. Ezek. 34:10 

They have mouths, but do not speak; eyes, but do not see. Psa. 115:5