In reallife do you suddenly get black around your eyes no. But the outside gets blurred yes because you don't stare at it.
Guess what happends when you focus ingame suddenly you can focus better on idividual pixels and the outside is blurred because your own eyes REAL focus. How more realistic can you get? Well 1 way see as zoomed in as you standard would in reallife so judging distances can be easy. Your distance although its not a clear view Flatland and no really visible enemy. But i'd guess around 100 meter.
Here's a fun thing to do. Grab a passer or whatever that device is called you draw circles with. Put it as close as possible to your eyes. Then put the feet of the device out of each other from your eye and sitting position till you get the width at the end of the points of the passer. Then measure the angle of the feet.
Go in practice mode open up the console with ~ type in Fov NUMBER
make the number angle you measured from the passer. Now what you can accuratly judge distances as good as you would normally
for most people the angle will probably be around 40 or 50 degrees. (ingame the default is 85) it would be great if that angle would have been lowered to 70 to get some sort of a compromise for seeing broad and ability to judge distances and hit at far ranges.