"omni"-prefixed word for "all seeing"?
The only actual Latin word that means ‘all-seeing’ which I can find is omnituens, which is frightfully rare and poetic even in Latin, and doesn’t seem to have been used more than a small handful of times in English—half of them being people telling others that there’s no such word.
I would not advise using that.
Then there’s omnipercipient, which is at least an English word, though still not a common one. It clearly means ‘all-perceiving’, but that’s quite close to ‘all-seeing’, and the OED defines it as “seeing or perceiving everything”.
All in all, though, I think you’d be better off with Greek than Latin here. The Ancient Greeks had tons of verbs meaning ‘see’ in various shades, and a few were combined with the prefix pan(t)- ‘all’, the Greek counterpart to Latin omni-. Thus, for instance, πανόπτης panóptēs means ‘all-seeing’ and has actually come down to us in English as panoptic, which has two separate meanings: OED
- All-seeing; (fig.) comprehensive, covering every aspect of a subject, all-encompassing.
- Of the nature of or relating to a panopticon; in which all can be seen.
In addition, there is pantoscopic, which is most commonly used as a synonym for bifocal (describing glasses and lenses), but also has a more generic meaning: OED
- All-seeing; having a wide range of vision or coverage.
Based upon this page, I believe you are seeking either:
omnividence - Being able to see everything or perceiving all things.
or
omnivision - 1. Seeing everything or perceiving all things.
Based on the latter word, omnivisual would seem a more likely candidate over omnivisient.
I found a word, "omnivident", with this meaning as an answer in a word puzzle magazine. (Acrostica, vol.1, puzzle #15, clue word M.) I was not able to find this word in a brief search of online dictionaries. Although I've never heard of this word before and it doesn't seem to be common-- to wit, not in dictionaries-- I can see why it would have that meaning. The magazine's editors must have SOME substantive basis for using "omnivident" in one of their puzzles.