Forgive my lack of VR knowledge, but it seems counterintuitive to me that the focal length on a headset like this would be fixed. Maybe 1-2 meters for large floating virtual work displays, but what about the "movie theater" scenarios where a giant screen appears to be quite a bit further away. Won't your eyes focus be adjusting to that simulated distance? What am I missing here?
It definitely feels different to me when my eyes are focused a few feet away vs across the room vs in a movie theater. Doesn't VR/AR trick our eyes into those further focal points? I'd think that was part of the effect/illusion.
I tried to explain this in an earlier post, but when you are using VR, it is no different than looking at a monitor or a picture on your phone. You are effectively looking at a monitor that is just in front your eyes, and so the focal length is fixed. The reason that the focal length is 1-2 meters rather than just a couple of cm is because there are some optical elements in from of the screens that effectively change the focal distance to be further away.
The two different screens present images designed to appear 3D and trick your mind into thinking that objects are closer or further away than what you are actually focusing on. Luckily, your brain uses the stereo images from your two eyes to judge distance (rather than the distance that your eyes are focusing on) which allows the 3D trick to work.