Definitions for "Eye Relief"
The distance behind a riflescope's eyepiece at which you can see a full sight picture.
the distance from the firing eye to the rear sight; eye relief is a function of stock weld Fahrenheit FDC fire direction center FFL final firing line FFP final firing position FLOT forward line of own troops FM frequency modulated FO forward observer fps feet per second FRAGO fragmentary order freq frequency FSK frequency-shift keying ft feet FTX field training exercise
The distance from your eye to the top of the eyepiece when you can see the entire (or largest) field of view.