Ask HN: Counting every unique sight in a lifetime

Pondering while walking that our eyes fall on innumerable objects, places, faces, even digital media like photos, videos and so many things around us (both physical and digital subjects).

While there is some work done on how much of it can we remember at a given time, do you wonder how big our entire visual vocabulary be if we count every object, face, place (any subject that can be uniquely, visually memorized - physical or digital) that falls before our eyes, and sum up the count over our lifetimes ?

This will vary between people and their environments, but I am still amazed by the potential size of this passive count of subjects that we process visually, even tough we may forget much of it.

How would one go about estimating an approximate range of total things that we see in our lives? It'd be our personal visual entropy vs others.