I suspect latency will be a problem. As your eye scans around things will "come in to focus" and that will be noticeable. Another issue is how wide the normal

I suspect latency will be a problem. As your eye scans around things will "come in to focus" and that will be noticeable. Another issue is how wide the normal eye jitter is. There is a normal 30-100Hz jitter in eye aiming that will require your high quality area to be larger than 2°, but I don't know how much. One last trick, the low resolution areas will need to be the correct average brightness. For many surfaces this is easy, but if you imagine a surface with a tiny, bright reflection... you could miss that until you processed it at full resolution making a bright spot that only exists if you look at it.