GOD'S WORD® Translation
They don't know or understand anything. Their eyes are plastered shut, so they can't see. And their minds are closed, so they can't understand.

American Standard Version
They know not, neither do they consider: for he hath shut their eyes, that they cannot see; and their hearts, that they cannot understand.

Berean Study Bible
They do not comprehend or discern, for He has shut their eyes so they cannot see and closed their minds so they cannot understand.

Douay-Rheims Bible
They have not known, nor understood: for their eyes are covered that they may not see, and that they may not understand with their heart.

English Revised Version
They know not, neither do they consider: for he hath shut their eyes, that they cannot see; and their hearts, that they cannot understand.

King James Bible
They have not known nor understood: for he hath shut their eyes, that they cannot see; and their hearts, that they cannot understand.

World English Bible
They don't know, neither do they consider: for he has shut their eyes, that they can't see; and their hearts, that they can't understand.

Young's Literal Translation
They have not known, nor do they understand, For He hath daubed their eyes from seeing, Their heart from acting wisely.

Isaiah 44:18 Additional Translations ...