How a NVD can be focused?
– A regular scope has an objective lens and eyepiece adjustment. First, adjust the objective lens to perfect the image. Then adjust the eyepiece to your eyesight. – In binoculars or goggles each eyepiece must be adjusted separately. To do this close your left eye and adjust the right eyepiece. Then open you left eye and adjust the left eyepiece to get a full contrast image. Some night vision goggles require objective focusing first, and then adjusting the eyepieces. NB: Remember that all night vision devices have a minimal focusing distance, a minimal distance at which objects can appear in full focus.
