I do almost exactly this, but instead use a cheapish 65" 4k/60hz TV instead. I can see bits of my surroundings with my peripheral vision, but only with the parts of my vision that are already blurry.

I suspect that 85" was chosen to maximize immersion for gamers (cover the entire field of view), rather than to minimize eyestrain. For me doing development work on a 65" from about 1.5m is close to ideal.