Our brain has a 3D slice sense of what is around us, so all the vision sense would need is an ability to see that 3D slice from different perpendicular directions all the way around in 4D. That’s what we already have with Visual Reorientation Illusions (VRIs), which is a necker cube-like flip that could be possible for a 4D being in 4D space with its 3D slice viewpoint. I’ve been working with ChatGPT4 and just got access to its ability to directly illustrate with DALLE3, which came up with this illustration about this idea.

What I really like is that it shows how a 4D eye spans into 4D space and would allow the perception of the 3D slice it is looking at from different ways. It’s hard for a 4D idea to be shown in a 2D image but it does its best to do so. Also DALLE3’s spelling ability is still being worked on, but hopefully will improve in the near future.