Antonyms for the phrase "catch sight of" include losing sight of, ignoring, and overlooking. Losing sight of implies that one does not get a glimpse of something or loses it while it is in view. Ignoring means not paying attention to something or someone deliberately. Overlooking means failing to observe something that should have been seen. All these terms denote a lack of focus and attention to details. By contrast, to catch sight of something refers to the act of noticing, observing, or becoming aware of something. It is a keen sense of observation and attention to even the tiniest detail that sets it apart from its antonyms.