Vision greater then 40; what does it really mean in game terms?

[iCaMpWiThAWP]

seeing through smoke is one of the greatest benefits, but in low vis. battles, whoever has the better imaging equipment should win, just try fighting poor armies with, say, USMC at less than 10 hexes visible, you can hit them while they can't even see you, i also think that a greater vision rating makes your ability to find concealed enemies better.