Not used on its own in modern Chinese; a literary word, often a variant of 杳 (dim and distant), seen in old phrases like 窅然 (profound; remote). It is the cave radical 穴 over 目 — an eye in a hollow, picturing sunken sockets.
register
Archaic and literary only; encountered in classical poetry and prose, never in everyday speech.
The eye sitting under the cave roof. Combined, the parts depict a deep-set, hollow eye, which extends to the figurative sense of something remote and hard to see, as in 看.