Binoculars equipped with focus adjustment nut 53 to which left object lens holder 42 of the left optical system is linked, dioptric adjustment nut 61 to which right object lens holder 41 is linked and which is attached such that it may move relative to focus adjustment nut 53, and focus adjustment dial 51 and dioptric adjustment dial 63 to move said nuts, respectively. When dioptric adjustment dial 63 is operated, dioptric adjustment nut 61 moves along the optical axis, together with which movement right object lens holder 41 linked to dioptric adjustment nut 61 moves, whereby dioptric adjustment is carried out. Focus adjustment dial 51 is located on either the top or bottom surface of the binoculars, and dioptric adjustment dial 63 is located on the other surface.