The antonyms for the word "became visual" are "disappeared," "vanished," and "faded." These words imply that something that was once visible or easily discernible is no longer present or detectable. In contrast to becoming visual, these antonyms suggest a gradual or sudden disappearance, a loss of clarity or definition, or a complete absence of visibility. While becoming visual implies a heightened state of awareness or perception, the antonyms suggest a diminishing or fading of perception or attention. Antonyms can help to expand our understanding of the nuances of language and the different ways in which words can express meaning.