I didn't need coffee and saliva all over my monitor. Now I need to clean it, thanks.
I knew you wouldn't understand it, no problem. When I wrote "there is only so much your eyes can see", it wasn't meant literally.
I'll explain it to you while you clean your monitor. Back then, with trully limiting hardware, a dev tried to build a tree in a 3D world. He didn't have much resources. So he had to make a very basic tree. Just a few polygons and very simple geometry for the trunk, the same for the top. Put a little colour on it, and that was the best a tree could look like back then.
Did the gamers "saw" it as a tree? Probably yes, because it kind of looked like a tree. But still, they also saw that the difference between a real tree (that their eyes are familiar with) and the basic polygonal tree was pretty big.
Where their eyes "pleased"? Probably not. But nowadys trees look so much better. The gab between what a real tree looks like and what a digital tree looks like is much much smaller. It's much easier for your eyes to see it as a real tree, since it already looks almost like it's counterpart.
Same goes for humans, lighting and other stuff. The illusion is already "sufficient" I believe.
Here are some pics of a game that's ten years old. It was made on hardware that is 10x or 15x weaker than PS360. Yet, the trees look like trees to me. My brain has to tell my eyes to look very closely to see imperfections. But at first glance (and even beyond), provided I'm not trying hard to convince myself otherwise, I not only "see" the trees, I can almost smell them.