unable to perceive visually due to distance, darkness, or physical obstruction

Long time no see.

not necessarily; not always the case

to turn a blind eye to; to ignore

not be able to hear

not well-known or famous; literally, a name not encountered in the classics

pitch-dark; so dark that one cannot see one's own hand

what remains unseen is deemed to be clean; to ignore unpleasant or unsanitary things to avoid distress or disgust

all black, no daylight; a world without justice

(idiom) to cross paths regularly (e.g. of people living or working in close proximity)

refuse to be convinced or admit defeat until faced with grim reality or disaster

to refrain from acting or committing resources until success is guaranteed or a target is in sight

lacking fame or recognition; unknown or not authoritative

To be unable to see one's own faults or fail to recognize one's own shortcomings.

to avoid seeing someone or intentionally refuse a meeting

no trace to be seen

be sure to wait; an agreement to stay at a meeting place until the other person arrives

to have disappeared, to be missing, or nowhere to be found

historically unique or unparalleled; having no predecessors and no successors

can't see the wood for the trees; failing to see the overall situation due to focusing on details

so deep that the bottom is not visible to the naked eye

casual acquaintances should not come between relatives; blood is thicker than water

what the eye doesn't see, the heart doesn't grieve over

one day apart seems like three years