The aspect ratio of an image is its width divided by its height.

---

in that sense, I don't think wee can really define the aspect ratio of human vision. Anyways.. our sight is organic. That is to say, wee see the world in real view as per the angle of incident light. Wee can see sharply till 45degrees. Also not to mention the fact that wee see in real time in 3D. You cannot assign a aspect ratio to an image that doesn't have defined border!