Unless you are on foot, the deer is only 5 yards away and you have a clear shot, I wouldn't take it. As stated previously, the smallest obstacle will send your arrow off target.

I will not shoot at a deer in a corn field from my stand. It's too risky. I have hunted corn fields on foot before and it is very frustrating. It's noisy and the deer are always 4-5 rows or more away from you. You can see them but they don't present you with a good shot. I would concentrate more on finding where they are entering and exiting the corn fields at and place you stand or blind there.