That only really works when combined with low-latency eye tracking. Yes, whatever we don't look directly at is really blurry, but our eyes move.

On the other hand, eye tracking is just about ready already. I've heard Google is working on a VR system using foveated rendering with tracking.

Not important. Rendering performance is not what limits the FOV. It’s the display technology.

> Consider foveation as well — only a small part of that is truly in “focus”.

Here's an optical illusion which illustrates how surprisingly tiny your fovea's FOV is: https://www.shadertoy.com/view/4dsXzM .

From glancing at the edges of my glasses, about 160-180 degrees, but anything close to the edges is always blurry; there's no way to avoid some level of lensing error. (Barring contacts.)

I've always favored extra-wide glasses, though. Some of the smaller ones might be 140 or even 120 degrees.

Interesting question, but I'm not sure how relevant that is. Try covering the parts of your view beyond the edges of your glasses, e.g. with your hands, and see if the experience is the same as with just your glasses. I bet there is a huge difference.

I think the issue is that the parts outside your glasses are blurry anyway (even for people with perfect vision), but even the blurry part is important for the experience.

When I configure FOV in "Sites in VR", I can see 110°. Maybe I'm wrong, because I have no other gadget to compare.