You can use gun sights in the real world while keeping both eyes open (and some schools of thought recommend it for situational awareness). It's not even that hard so long as your dominant eye is the one looking through the sights, and you don't get wink fatigue either.
I suspect the VR game isn't correctly simulating what this actually looks like, though.
I suspect the VR game isn't correctly simulating what this actually looks like, though.