Night Vision Rifle Scope Diopter Adjustment Range: -4 - 4 dpt

A diopter adjustment range of -4 to +4 on a night vision rifle scope refers to the ability to fine-tune the focus of the reticle (the crosshairs or other aiming point) for the individual user's eyesight. The range of -4 to +4 means that the user can adjust the focus from slightly blurry to slightly sharper, over a range of 8 levels of adjustment. The diopter adjustment is typically located near the eyepiece of the scope and can be adjusted by turning a small knob or ring.