invisible
in-vis-i-ble
adjective
Unable to be seen; not perceptible to the eye.
"The tiny particles were invisible without a microscope."
Thesaurus
Synonyms: out of sight, infrared, occult, nonvisual, unseeable, undetectable, camouflaged, hidden, lightless, ultraviolet, concealed, unseen
Antonyms: conspicuous, seeable, visible