How Scope, Prism Sight and Magnifier Eye Relief Affects You
Eye relief is a simple concept but depending on your gun and optic, it can take some experimentation and thought to keep it from being a hindrance to you.
The eye relief of a magnified optic is the distance from the rear of the sight your eye can be and see through it. Unmagnified sights have unlimited eye relief.
Whether you’re using a scope, prism sight, or magnifier, the principles are the same. If the outside of your view through the optic starts going black, your eye is either too far or too close to the optic or not centered enough. The closer your eye is to a magnified optic, the bigger your field of view will be. With everything else being equal, long eye relief optics have a smaller field of view than optics with shorter eye relief.
With variable magnification scopes, the higher you adjust the magnification, the closer your eye will need to be, and the smaller the range of distances your eye can be and still see through the scope. If the scope is positioned ideally, this will usually only cause an issue if you’re on the higher end of magnification and your body/neck is very upright like when standing straight or if you get very close to the scope when prone. Having extra materials that your stock is against like armor, padded shoulder straps, buckles or thick jackets will push the rifle farther from your body and require you to get your head farther forward than you would without wearing those things or you will have to adjust your stock if it can do so. With the range of eye relief that most scopes have, the scope will usually need to be mounted where you’re required to hunch forward/bring your neck forward when your upper body is straight in order to see through the scope on higher magnifications so that you won’t be too close to it when you’re prone, which forces your head to naturally be closer than when in other stances. Depending on your body and what you’re wearing, your stock may need to be lengthened when prone or aiming at a significant angle upwards relative to your upper body in order to maintain proper distance.
Test your magnified optic on your gun and see if you can use all your shooting positions, even the less frequently used ones, without running into eye relief problems. If you have an adjustable stock, make sure it’s at the length you want to use. Move the optic and test again until it’s in the position that’s easiest for you to work with.
