[blakecaldwell]

It's not just sharpness of focus. There's that, because of - I believe - how densely different areas of our retinas are populated with cones and rods. That's not the same thing that's going on when you look at a tree in front of you, and then the mountains miles away.

The screen is flat. If you were playing a game that occupies 3D space, the game could mimic real depth by changing how it looks depending on where you're looking. It would blur things as they'd be blurred in real life. Or maybe they'd double up things close to us when we look far away, like when you hold a finger in front of your face and then stare far away, or vice-versa. I think we probably rarely notice these things in real life. Maybe this would make it feel magically more real.