Your brain puts together multiple 3-d cues. If you are looking directly at something the angle of your two eyeballs is a little different dependening on the distance and this is vergence.

Your eyes also focus like the autofocus of a camera and the cue from that is called accommodation.

The two should match to provide perfect perception on reality. Certainly a VR headset works with a fixed focus for everything, but to get the ultimate perception of reality without eye strain a VR headset should be able to simulate focusing distance.

(Who knows, however? Meta’s Super Bowl ad might be revealing their real intentions. In that ad a discarded animatronic Android gets to relive its past with VR. VR is good for the elderly because you can enjoy it without learning anything new. I think one of the worst things about getting old that I experience is presbyopia where you can’t focus over the whole range so you have to wear two pairs of glasses. Maybe I’d find it easier just to have it all in focus all the time.)