Field of view Field of view is the extent of the view you have through the glasses. Field of view is expressed at a range of 1000 meters. The greater the magnification, the narrower the field of view. Higher magnification and narrower field of view, make binoculars harder to hold still without support. The ocular lens is the one through which the user sees the image in the binoculars.
Eye relief is the distance from the ocular lens to the user's eye.
In order to see the complete image clear by and sharp, the distance must be correct. If you wear glasses, you should choose a type of binoculars with eyepieces that can be pushed or folded in, since glasses offset the distance of the eye to the lens. Size Compact binoculars are small and light, but have smaller and less bright lenses. Full size binoculars allow one to see a brighter image, but are larger and heavier. Give a good thought to how you will be using the binoculars and under what conditions.