||The distance between the surface of the eyepiece and the point where the pupil is positioned for full field of view.
||The (usually largest) lens at the far end of a binocular, monocular or telescope.
||The set of lenses and the mechanism that holds them into which the user looks when using an optical instrument.
||Stands for InterPupillary Distance and is the measure of distance between the centres of the pupils of your eyes. Your optician will be available to provide you with this information after an eye examination.