TgJ Ez13:22 :חֲלָף דְאַכהִיתִין לֵב זַכַי לְמִהוֵי שְקַר וֻמִן קְֹדָם מֵימְרִי לָא אִתכְהִי‏ : because you have made the innocent heart dull, to become a lie, and it was not made dull by My Memra
See the entire entry for khy vb. (eyes) to fail