Like Leo, you’re using words you don’t actually understand. You say “entire universe” as if that’s a tangible, total thing, but it’s not. There is no “entire.” You’re assuming the universe is some fixed, completed totality that can be seen or grasped, when in reality it’s a constant flux, an ongoing creation, not a static whole. So the very phrase “entire universe” is incoherent. Just like there is no 'everything.' Just like there is no 'infinite'. And the universe is not 'infinite'. And you don't live in an 'infinite' reality. It's indefinite, indeifnite, and indefinite.
You couldn't even know what you mean by "Universe", let alone "entire". So, you're not really saying anything.
At best, you might’ve observed yourself from a certain zoomed-out perspective or had visuals of planets, space, or some images you associate with "cosmic imagery". But that doesn’t mean you saw the universe, it just means you hallucinated symbolic representations of it. Even an out-of-body experience wouldn’t make that claim valid.
Saying “I saw the universe behind my eyes” makes no sense because the universe is out there, external to you. What you saw was in your mind—subjective imagery, neural fireworks, psychedelic patterning, not the universe itself. Because that makes no sense.