This is a theory on how a head mounted display can show stereoscopic images and a large field of view.
Starting with the stereoscopic first.
The image being shown to the eye, is seen by the eyes at two different horizontal perspectives.
If you hold a pencil vertically and in front of you, your eyes are cross eyed as you focus on the vertical pencil.
Then move the pencil to the left or right until only one eye sees the pencil.
The pencil is now not visible to the two eyes but it is visible in your field of view.
So by only the field of view seeing it but not two eyes, the image stops being stereoscopic.
So there is a part of the display or image being shown to the eye that is supposed to be stereoscopic,
and part that is only the field of view and not stereoscopic.
As you may or may not know, the Oculus VR is using only the one stereoscopic position, focusing at infinity.
But true stereoscopic images has positive, negative, and zero parallax; three types of stereoscopic images.
My solution is to wear shutter glasses over the eyes, then have the LCD screen behind the shutter glasses.
Then when the left eye shutter closes, the display shows one image,
and then the right eye shutter closes and the left eye shutter opens and the display shows a new picture.
The pictures shown to the eyes are stereoscopic pictures, not just focusing at infinity.
Part of the stereoscopic picture the eye sees is being fused in the brain so it's stereoscopic,
Part of the picture belongs only to the field of view.
Because the glasses are worn,
I suspect a custom type of shutter glasses that lets the field of view be non-occluded be visible would be necessary.
So the glasses would look like they belong to a clown.
And since the glasses extend about a inch past the eye brow, a large monitor would be necessary,
like a iPad mini screen.
I'll draw up some pictures, but I warn you, I don't draw very well.
With the HMD now able to show 3D stereoscopic images, there can be eye tracking.
Eye tracking is so if the eye looks in virtual reality, it sees that in stereoscopic 3D, the far and close distance is in 3D. Things you see, can move in the three different types of stereoscopic parallax in virtual reality.
I won't build this myself, I would need to be a hardware genius to rig up some 3D shutter glasses into something like the Oculus which uses a ipad mini screen, and that's not even mentioning they're odd use of glass.
If of the shelf 3D TV shutter glasses are used, which initially for testing purposes it will have to be, then the field of view will be reduced.