The eyes represent seeing, and seeing represents thoughts or judgment. Alternate translation: "considers themselves pure" or "believes they are pure" (See: [[rc://en/ta/man/translate/figs-metaphor]])
The words "washed" and "filth" speak of God forgiving people who sin as if he were washing physical filth off of the people. This can be translated in active form. Alternate translation: "God has not forgiven them of their sins" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])