If you put your eye three inches from the ocular of a rifle scope with a 4.5-5 inch eye relief, you will see nothing. Your eye has to fall inside what's known as the eye box of that scope to see the image. Eye box refers to the leeway, fore and aft you have in placing your head on the rifle stock.
One of the most important things in choosing a scope is the question as to how well you can position it so that you place your head inside the scope's eye box. I've learned, for instance, that I can use only about 4.5 inches or eye relief with my build ( long neck) and the dimensions of the stocks on my rifle. I do insist, however, in using such scopes. The dead minimum that I will use is about 3.5 inches. Even then, it must have lots of leeway in head position or I'll look for something else.
While this may sound like alot of trouble, I've found that it is well worth it. Especially if you ever need to shoot in a hurry at a fast moving animal. It is also important if you shoot from different positions, and hunt in a wide range of temperatures.
